Research Article | | Peer-Reviewed

Conic Projection as Manifold and 3-Sphere Dihedral Angles θHnHn+1[Deg] Under Homotopy

Received: 20 January 2026     Accepted: 30 January 2026     Published: 26 February 2026
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Abstract

Conic projection as manifold enable calculation dihedral θHnHn+1[deg] angles from differences between two atoms of carbon ΔδCnCn+1[ppm] in three steps or from only one atom of carbon δCn[ppm] in close relationships with tetrahedral φCn[deg] angles under 3-Sphere approach. Hopf fibration and Lie algebra ensuring calculation dihedral θHnHn+1[deg] angles from vicinal ϕ[deg] angle, angle results from vicinal coupling constant 3JHH[Hz]. Real Hopf fibration for calculation dihedral θHnHn+1[deg] angle in real space, and R16 octonionic Hopf fibration, double of quaternionic R7, for all cis, trans-ee, trans-aa stereochemistry, unreal space relative to calculated dihedral θHnHn+1[deg] angle. Continue “deformation”, homotopic behaviour h ⇆ h-1 characteristic for wave NMR data, probably a point of swich on Möbius band, in case of radius r of the cone inscribes on sphere at tangent point, calculated from height of cone h or inverse of height h-1, the tan function of h is equal with sin function of h-1. Dihedral θHnHn+1[deg] and tetrahedral φCn[deg] angles are from the trigonometric point of view under sin and tan function, or viceversa, homotopic behavior of NMR data under conic projection demonstrating that. Because the dihedral θHnHn+1[deg] angles are not found in first unit, for few vicinal coupling constants 3JHH[Hz], the rule accepted until now are explored taking in consideration other sets for building unit along the set C, respectively D, E and F, G, or vicinal angle ϕ[deg] with its three possible dihedral θHnHn+1[deg] angles in close relationships with tetrahedral φCn[deg] angles under seven sets unit. Building units through sets U or S calculated from sin or tan functions until calculated angles are almost equals with angles of unit U1 or S1, required long time for calculation.

Published in Science Journal of Chemistry (Volume 14, Issue 1)
DOI 10.11648/j.sjc.20261401.12
Page(s) 12-24
Creative Commons

This is an Open Access article, distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution and reproduction in any medium or format, provided the original work is properly cited.

Copyright

Copyright © The Author(s), 2026. Published by Science Publishing Group

Keywords

Conic Projection, Homotopy, 3-Sphere Dihedral Angles, Tetrahedral Angles, Vicinal Coupling Constant

1. Introduction
The invers of any closed curve on S2 will be an immersed torus in S3, and any compact Rieman surface of genus 1 can be embedded in the unit sphere S3CR4 as a flat torus. The embedding can be chosen as the intersecting of S3 with a quadric hypersurface in R4 . As claimed by Willmore Conjecture surface in R3 rather as S3. Surface in 3D Euclidean space R3 is study with Möbius differential geometry, measurement of angles instead of lengths, i.e. Plank-Einstein versus De Broglie .
Conic projection used on spherical map calculation (i.e. earth map), convert the latitude and longitude coordinates into two-dimensional coordinate, cartesian coordinate. Point of sphere or spheroid are transformed in tangent or secant of cone that is wrapped around the sphere (Figure 1, eq. (1)-(3)) .
θ = sec-1h(1)
r= (h2- 1)1/2/h(2)
z = cosθ = 1/h(3)
Where: h – height [radieni], r – radius of cone inscribes on sphere at tangent or secant point of the cone outside of sphere [radieni].
Six dihedral angles with cis, trans-aa, trans-ee stereochemistry can be represented on three concentric cons in 3D and on two intersecting circles in 2D. Point of intersection in 2D between two circles are half ϕ1A and ϕ1B, first angles of sets A and B or half angles ϕ1A or B/2 between trans-ee3,2 and trans-ee4,1. Inside of the 3-Sphere, a hypersphere in 4D, are easy to drawn three sets angles, third set intersecting sets A and B at half first C angle, angle used for increased number of units .
Figure 1. Conic section representation.
Figure 2. Dihedral and vicinal angles on 3-Sphere representation.
2. Results
Dihedral angles are calculated with conic projection (Figure 1) from differences between two atoms of carbon or one atom of carbon in 3 steps as presented in Tables 1, 2 for iminocyclitols 1 - 8 (Figure 3) . The wave character of NMR data preserved homotopy, and angles calculated are under height h or invers of height h-1 since the calculated vicinal angle must be almost equal with the recorded one or with very smaller differences. The tan function of h-1 is equal with sin function of h ensuring the trigonometric rule between dihedral θHnHn+1[deg] and tetrahedral φCn[deg] angles of five membered ring (Table 2).
Figure 3. Iminocyclitols with 1-α-D (1 – 3, 6 - 8) and 1-β-L-stereochemistry (4, 5, 9, 10) bearing at C1 one alkyl chain or two alkyl chain.
2.1. Method for Calculation Dihedral Angles in Three Steps
Step 1: Height of cone outside of sphere (eq. (5)) will be calculated from differences between two atoms of carbon ΔδCnCn+1[ppm] under Euler conic manifold (eq. (4)). The angle θAIn [deg] calculated with cos function from differences between two consecutive atoms of carbon chemical shift is transformed on first angle of the set A and calculate height of cone.
cos-1Rm= θAin(4)
Where θAIn → θAI1, n = 1 – 6.
cosθAI1= 1/h(5)
Table 1. Dihedral angles θHnHn+1[deg] calculated from differences between two atoms of carbons chemical shift ΔδCnCn+1[ppm] with conic projection for iminocyclitols 1-9.

Comp

3JHHa [Hz]

Φ [deg]

ΔδCnCn+1 [gaussx10]

θAin [deg]

θAI1 [deg]

1/h h [π]

r [π]

θAIIn [deg]

ϕ [deg]

3JHnHn+1 [deg]

θHnHn+1 [deg]

1

4.1

67.24

0.755

39.11

20.88b

h-1: 0.934

0.381

22.43

67.56

4.109

22.43

16.81

h: 1.0703

0.356

20.88b

69.11b

4.15

20.88

5.4

116.64

0.022

88.71

28.71

h-1: 0.877

0.547

33.219

116.78

5.40

-26.78

29.1

-41.756

30.312

119.363

5.46

-41.073c

28.715

5.35

-33.219

1.1402

0.4804

28.715

118.715

5.44

-28.715

118.420

5.44

-40.428c

0

0.515

58.97

1.024

0.999

0.0178

1.0247

1.02471

0.5060.

-88.97, -91.024

1.0001

0.0178

1.0246

0246

506

-88.97, -91.024

2

3.1

38.44

0.3949

66.736

6.7366

0.993

0.1181

6.7837

38.69

3.11

-53.216

9.61

40.24

3.17

-32.861S3

9.648

3.106

-9.514d, US

9.648

3.106

-9.788d, US

39.648

3.14

50.351US

1.0069

0.1173

6.7366

38.691

3.11

-53.263

9.790

3.12

-9.936

9.70

3.12

-9.936

39.790

3.15

50.209

3.9

60.84

0.0056

89.679

29.679

0.8688

0.5699

34.743

60.320

3.88

-34.743

15.21

62.530

3.95

-41.581

1.1509

0.4951

29.679

60.320

3.88

29.679

62.617

3.95

-40.106

15.160

3.89

-14.655e

8.8

77.44

0.1372

82.110

22.110

0.9264

0.4062

23.971

78.014

8.82

-167.74,

-135.63

309.76

1.07938

0.3764

22.110

78.944

8.88

-168.73,

-135.53

3

4.8

92.16

0.24649

75.729

15.729

0.9625

0.2816

16.358

92.716

4.814

-/+2.716S2

23.04

1.0389

0.2710

15.729

92.918

4.8519

-/+2.918S3

5.2

108.16

0.0420

87.591

27.591

0.886

0.5226

31.507

108.457

5.207

19.497

27.04

27.591

5.25

-31.507

1.1283

0.4631

27.591

28.188

5.30

-32.408

0

0.13165

82.434

22.434

0.9243

0.4128

24.386

2.8069

0.83

-87.193

1.4034

0.601

-88.596

1.08188

0.3816

22.434

1.8913

0.687

-88.108

4

4.8

92.16

0.07563

85.662

25.662

0.9013

0.4804

28.715

92.568

4.81

-/+2.568

23.04

1.10943

0.4330

25.662

92.168

4.8

-/+2.168

5.2

108.16

0.04481

87.431

27.431

0.8875

0.5190

31.268

27.431

5.23

-31.268

27.04

108.524

5.20

-19.577

1.12667

0.4606

27.431

27.442

5.23

-31.284

108.520

5.20

-19.571

0

0.05042

87.109

27.109

0.8901

0.5119

30.793

0.793

0.44

-89.206

1.12342

0.4556

27.109

1.445

0.60

-88.554

5

2.8

31.36

0.24649

75.729

15.729

0.9625

0.2816

16.358

31.048

2.78

-27.283

7.84

8.09709

2.84

-8.1791

1.03890

0.2710

15.729

31.459

2.80

58.545

2.8

-37.135

2.8

-27.556

7.7917

2.79

-7.8647

3.6

51.84

0.03641

87.913

27.913

0.8836

0.5297

31.989

51.3264

3.582

38.6736

12.96

-37.9798

-53.1678

1.13165

0.4681

27.913

51.3912

3.584

38.6087

-38.0049

-52.9908

8.8

77.44

0.26610

74.567

14.567

0.9678

0.2598

15.062

322.46

8.97

142.468

309.76

79.958

8.94

169.958

1.03321

0.2515

14.567

310.417

8.8

142.716

79.711

8.92

168.711

6

4.9

96.04

0.19607

78.692

18.692

0.94725

0.3383

19.775

24.887

4.98

-22.823,

-27.640

24.01

1.05568

0.3294

18.692

24.618

4.96

-22.615

24.346

4.93

-22.403,

-26.903

0a

0.21848

77.379

17.379

0.95434

0.3129

18.239

2.64

0.812

-87.35

1.04783

0.2987

17.379

3.93

0.99

-86.06

7

7.6

231.04

0.10364

84.051

24.051

0.9131

0.4462

26.506

230.54

7.59

37.67

57.76

1.0950

0.4075

24.051

58.253

7.63

31.746

58.253

7.63

-40.377

58.253

7.63

-38.224

3.8

57.76

0.29971

72.559

12.559

0.9760

0.2120

12.242

58.061

3.809

-38.563

58.031

3.808

-38.616

57.872

3.80

32.128

-40.259

-38.901

14.44

1.0245

0.2174

12.559

58.565

3.79

-37.677

57.559

3.79

32.440

-40.162

-39.465

8

6.6

174.24

0.10364

84.051

24.051

0.9131

0.4462

26.506

43.253

6.57

46.746

43.56

1.09507

0.4075

24.051

174.018

6.57

-/+5.948

3.5

49

0.29971

72.559

12.559

0.9760

0.2227

12.864

12.5517

3.54

-12.864

12.25

1.02451

0.2174

12.559

12.2679

3.50

-12.559

9

7.3

213.16

0.112

83.56

23.56

0.916

0.436

25.86

214.13

7.31

-55.87, -42.67, 29.29

53.29

212.29

7.28

-57.93, -38.78, 27.96

1.090

0.399

23.566

53.566

7.31

36.433, -38.81, -47.57

213.217

7.30

-56.78, 28.71,

-40.90

4.5

20.25

0.3417

70.01

10.01

0.984

0.176

10.17

20.34

4.51

69.65

81

80.34

4.49

170.34

1.0158

0.173

10.01

20.008

4.47

69.99

80.008

4.47

170.01

a.1H, 13C-NMR data ind. 8, 9; b. θ(r(h))sin = θ(r(h-1)tan; c. six sets; d. U to S giving U; e. from set D ; d polyhedron; e.U to S giving U.
Table 2. Dihedral angles calculated θHnHn+1[deg] from carbon chemical shift δCn[ppm] with conic projection for iminocyclitols 1-10.

Comp

3JHH [Hz]

Φ [deg]

δCn [ppm]

δCn [gaussx10]

θAIn [deg]

θAI1 [deg]

1/h h [π]

r [π]

θAIIn [deg]

Φ [deg]

3JHH [deg]

θHnHn+1 [deg]

φCn [deg]

1

4.1

67.24

C1: 55.8

1.56302

50.224

9.775

0.9854

0.1722

9.9921

69.921

4.18

20.0787

109.88

16.81

1.0147

0.1697

9.7757

69.775

4.17

20.2242

109.96

C2: 83.5

2.33893

64.688

4.688

0.9966

0.0820

4.7039

117.52

5.42

-41.567

99.218, 101.563c

115.29

5.36

-25.296

102.655, 101.56b

29.654

5.44

-34.703

102.655, 101.56b

1.0033

0.0817

4.6895

117.53

5.42

-41.563

99.216, 101.567c

115.31

5.369

-25.310

102.663, 101.565b

29.645

5.44

-34.689

102.663, 101.565b

5.4

116.6

C3: 84.3

2.36694

65.008

5.008

0.9961

0.0876

5.0276

117.10

5.41

-41.675

99.162, 101.669c

29.16

114.97

5.36

-24.972

102.495, 101.669b

29.854

5.46

-35.027

102.495, 101.669b

1.0038

0.0873

5.0084

117.12

5.41

-41.669

99.16, 101.675c

114.99

5.36

-24.991

102.48, 101.67b

29.842

5.46

-35.008

102.48, 101.67b

0

C4: 65.9

1.84593

57.198

2.801

0.9988

0.0489

2.8048

2.8048

0.837

-87.195

106.39

1.0011

0.0488

2.8014

2.8014

0.836

-87.198

106.40

2

3.1

38.44

C1: 57.4

1.60784

51.541

8.458

0.9891

0.1487

8.5524

38.552

3.104

51.447

109.229, 106.917b

9.61

1.0109

0.1470

8.4587

38.458

3.1

51.541

109.276, 107.104b

C2: 71.5

2.00280

60.046

0.046

0.9999

0.0008

0.0462

60.046

3.874

29.953

104.97, 100.015b

1.0000

0.0008

0.0462

60.046

3.874

29.953

104.976, 100.015b

3.9

60.84

C3: 71.7

2.00840

60.138

0.138

0.9999

0.0024

0.1383

60.138

3.877

29.861

104.93, 100.061b

15.21

1.0000

0.0024

0.1383

60.132

3.877

29.861

104.93, 100.046b

8.8

77.44

C4: 66.8

1.87114

57.694

2.305

0.9991

0.0402

2.3081

76.154

8.72

-165.73

105.729c

309.7

79.230

8.90

-169.03

109.036

76.923

8.77

-166.56

106.571U2,c

76.923

8.77

-135.75

105.752d

1.0008

0.0402

2.3053

76.152

8.72

-165.72

105.731c

79.231

8.9

-169.03

109.035

76.926

8.77

-166.57

106.568U2,c

76.926

8.77

-135.75

105.752

3

4.8

92.16

C1: 63.7

1.78431

55.913

4.086

0.9974

0.0714

4.0966

23.598

4.85

-25.903

107.043

23.04

92.048

4.79

+/-2.04e

106.02

1.0025

0.0712

4.0862

23.606

4.85

-25.913

107.048

92.043

4.796

+/-2.04e

106.021

C2: 72.5

2.03081

60.500

0.500

0.9999

0.0087

0.5006

26.909

5.187

-30.500

104.749, 100.166b

109.83

5.21

19.833

99.916

1.0000

0.0087

0.5006

26.909

5.18

-30.500

104.749, 100.166b

108.74

5.21

19.833

99.916

5.2

108.1

C3: 74.0

2.06511

61.037

1.037

0.9998

0.0181

1.0378

27.275

5.22

-31.037

104.481, 100.345b

27.04

108.58

5.21

19.654

99.827

1.0001

0.0181

1.0376

27.275

5.22

-31.037

104.481, 100.345b

108.58

5.21

19.654

99.827

0

C4: 69.3

1.94117

58.992

1.007

0.9998

0.0175

1.0077

1.00771

0.501

-88.992

105.503, 109.664b105.502, 109.664b

41.000

80.017

41.007

.0075

0.501

-88.992

4

4.8

92.16

C1: 68.4

1.91596

58.538

1.461

0.9996

0.0255

1.4622

92.924

4.81

-/+2.92

106.461

23.04

22.541

4.74

-20.97

109.512

1.0003

0.0255

1.4617

92.923

4.81

-/+2.92

106.462

22.541

4.74

-20.974

109.512

C2: 71.1

1.99159

59.860

0.139

0.9999

0.0024

0.1396

26.661

5.163

-30.139

104.930

108.84

5.216

19.953

110.023

1.0000

0.0024

0.1396

26.661

5.163

-30.139

104.930

108.84

5.213

19.953

110.023

5.2

108.1

C3: 72.7

2.03641

60.589

0.589

0.9999

0.0102

0.5898

26.971

5.193

-30.589

104.705

27.04

108.71

5.217

19.8033

110.098

1.0000

0.0102

0.5897

26.970

5.193

-30.589

104.705

108.71

5.213

19.803

110.098

0

C4: 70.9

1.98599

59.766

0.233

0.9999

0.0020

0.1167

0.1167

0.178

89.883

105.116

1.0000

0.0040

0.2335

0.233

0.241

89.766

105.058

5

2.8

31.36

C1: 63.3

1.7731

55.668

4.331

0.9971

0.0757

4.3439

31.101

2.78

-37.104

109.33

7.84

7.1593

2.65

-7.104

109.33

32.008

2.82

-38.687

108.556

1.0028

0.0755

4.3315

31.105

2.78

-37.112

108.552

7.167

2.67

-7.112

108.552

31.994

2.828

-38.663

109.343

C2: 72.1

2.01960

60.320

0.320

0.9999

0.0055

0.3206

50.213

3.54

39.789

100.106

-37.539

101.229d

-56.383

103.191d

1.0000

0.0055

0.3206

50.213

3.54

39.786

100.106

-37.540

101.230d

-56.383

103.191d

3.6

51.84

C3: 73.4

2.0560

60.897

0.897

0.9998

0.0156

0.8974

50.598

3.55

39.401

100.2

12.96

-37.693

101.153d

-55.276

102.615d

1.0001

0.0156

0.8974

50.598

3.55

39.401

100.299

-37.693

101.153d

-55.231

102.638d

8.8

77.44

C4: 63.9

1.7899

56.035

3.964

0.9976

0.0693

3.9744

76.987

8.77

166.987

106.98c

309.7

1.0023

0.0691

3.9649

76.982

8.77

166.982

106.98c

6

4.9

96.04

C2: 78.4

2.19607

62.912

2.912

0.9987

0.0496

2.8471

24.530

4.95

-27.152

103.543

24.01

95.694

4.89

-5.694S2

102.687

95.666

4.89

5.694S2

102.687

23.700

4.86

-21.89U2

100.970

1.0012

0.0508

2.9120

95.824

4.89

-5.824S2

102.152

95.794

4.89

5.824S2

102.152

23.755

4.87

-21.94U2

100.949

C3: 85.4

2.39215

65.289

5.289

0.9957

0.0925

5.3122

95.312

4.88

-5.312

102.355

95.289

4.88

5.3122

102.355

1.0042

0.0921

5.2895

95.289

4.88

-5.289

102.343

95.267

4.88

5.289

102.343

0a

C4: 77.6

2.1736

62.609

2.609

0.9989

0.0455

2.6122

2.61222

0.808

-87.38

106.304106.306

61.001

70.045

2.6095

.6095

0.807

-87.39

7

7.6

231.0

C2: 84.2

2.35854

64.913

4.913

0.9963

0.0859

4.9313

230.65

7.59

-55.068

102.543, 101.637b

57.76

57.342

7.57

-39.862

100.086

1.0036

0.0856

4.9132

230.64

7.59

-55.086

102.534, 101.643b

57.361

7.57

-39.826

100.068

C3: 80.5

2.25490

63.673

3.673

0.9979

0.0642

3.6815

230.23

7.58

-56.318

103.163, 101.224b

229.77

7.57

37.363

101.326

1.0020

0.0640

3.6739

230.23

7.58

-56.326

103.159, 101.227b

229.73

7.57

37.347

101.318

3.8

57.76

C4: 69.8

1.95518

58.238

0.761

0.9999

0.0138

0.7612

57.851

3.80

-79.747

110.126, 108.77c

14.44

14.165

3.76

-105.38e

104.619c, 97.309

1.0000

0.0132

0.7612

57.851

3.80

-79.747

110.373, 108.77c

14.165

3.76

-105.38e

104.619c, 97.306

8

6.6

174.2

C2: 84.2

2.35854

64.913

4.913

0.9963

0.0859

4.9313

44.300

6.65

-34.931

102.54, 101.63b

43.56

1.0036

0.0856

4.9132

44.262

6.65

-34.913

102.53, 101.643b

C3: 80.5

2.25490

63.673

3.673

0.9979

0.0642

3.6815

43.159

6.56

46.840e

103.163c, 98.418

1.0020

0.0640

3.6739

43.163

6.56

46.836e

103.159c, 98.420

3.5

49

C4: 69.8

1.95518

59.238

0.761

0.9999

0.0132

0.7612

49.746

3.52

-82.65

108.675d

12.25

-62.149

106.074d

1.0000

0.0132

0.7612

49.746

3.52

-82.65

108.675d

-62.149

106.074d

9

7.3

213.1

C2: 84.0

2.35294

64.849

4.849

0.9964

0.0848

4.8667

213.59

7.30

-41.622

101.616c, 99.417

53.29

1.0035

0.8453

4.8493

213.58

7.30

-41.616

101.167c, 99.416

C3: 80.0

2.24089

63.496

3.496

0.9981

0.0611

3.5031

213.35

7.30

-41.167

101.165c, 99.417

1.0018

0.0609

3.4966

213.35

7.30

-41.165

101.167c, 99.416

4.5

81

C4: 67.8

1.89915

58.227

1.772

0.9995

0.0309

1.7734

20.629

4.54

170.295

109.852e, 110.295c

20.25

1.0004

0.0309

1.7725

20.630

4.54

170.295

109.852e, 110.295c

10

3.9

60.84

C2: 75.0

2.10084

61.575

1.575

0.9996

0.0275

1.5761

61.576

3.92

28.423

104.212

15.21

61.257

3.91

-40.525

100.525c

1.0003

0.0274

1.5755

61.575

3.92

28.424

104.211

61.257

3.91

-40.525

100.525c

C3: 68.8

1.92717

58.741

1.258

0.9997

0.0219

1.2584

61.258

3.91

28.741

104.370

61.608

3.92

-40.419

100.419c

1.0002

0.0219

1.2581

61.258

3.91

28.741

104.370

61.608

3.92

-40.419

100.419c

9.1

82.81

C4: 74.9

2.09803

61.534

1.534

0.9996

0.0267

1.5346

331.38

9.10

146.931

106.53

331.2

331.53

9.10

61.534

105.767

1.0003

0.0267

1.5341

331.38

9.10

146.932

106.534

331.53

9.10

61.534

105.767

a. 1H, 13C-NMR data ind. 8, 9; b. Six sets, c. tetrahedral angles characteristics for 5 rings on same set with dihedral angles, d. tetrahedral angle established for dihedral angle calculated from sin-1tan or tan-1sin function on same set, e. unit was build from set E instead C.
Step 2: The radius r of the cone inscribe on sphere at corresponding tangent point can be calculated from h or h-1 with eq. (6), then one angle of set AII with eq. (7) used for building units. Sometimes resulting directlly the vicinal angle or the dihedral angle, otherwise will be build units with seven sets angles.
r= [(a)2-1]1/2/(a)(6)
Where a = h or 1/h.
sin-1r = θAIIn(7)
Where θAIIn → units.
Units are build from calculated angle θAIIn in seven sets angles with possibility to increase to more units with set C, as a general rule used until now dihedral angles are considered in close relationships with tetrahedral angles between set A, B and D, E or F, G if dihedral angle is in set B. Alternatively, six sets angles, three sets angles of unit U and three of unit S, in first case with angles higher as 5[deg] and in second case smaller as 5[deg], totally 14 sets angles. In this paper some units are build from sets D, E or F, G, or sets F, G are transformed in A, B, as well as no more as three units CnNi = UnNi, SnNi are used .
Step 3: Characteristic equations for calculation dihedral angles – vicinal angles and vicinal coupling constant are used for choosing corresponding angles with calculated vicinal coupling constant values almost equals with recorded one.
Vicinal coupling constants are under two rules: Case 1: smaller vicinal coupling constant for trans-ee and cis stereochemistry and higher for trans-aa stereochemistry , iminocyclitols 1-6, 10, Case 2: higher vicinal coupling constant for cis stereochemistry and smaller for trans-ee and trans-aa vicinal coupling constant , iminocyclitols 7-9.
2.2. Calculated Dihedral θHnHn+1[deg] and Tetrahedral φCn[deg] Angles on Seven and Six Sets Unit
In Table 1 are calculated dihedral θHnHn+1[deg] angles for imoncyclitols 1 - 10 from differences between two atoms of carbons ΔδCnCn+1[deg]. Dihedral angles are chosen from sets A and B having in mind relationship with tetrahedral angles φCn[deg]. The presence of vicinal angles on sets A and B gives other possibility to calculate dihedral angles without building units (Table 1, comp 1, 3JH2H3 5.4[Hz]). In case of compound 2, vicinal angle ϕ[deg] under second rule results from unit US calculated from unit U1 with equation characteristic for transformation U to S (ϕ = 9.64 or 9.79[deg]). Dihedral angles θH3H4 and θH2H3 of compounds 2 and 10 are calculated from sets D or G, using a different way for building units, relative to increased units from set C. In this case was reduced the number of units, method used also in Table 2 for calculation dihedral angles of 3 in close relationships with tetrahedral angles from carbon C1 chemical shift δC1[ppm], or for compounds 9 and 7. In Table 1, compound 6, for a vicinal coupling constant of 4.6[Hz] unit was switch from set G to set A and angles are calculated from vicinal angles ϕ[deg]. Tetrahedral angle φC4[deg] for a vicinal coupling constant of 8.8[Hz] usually can be considered an angle from same sets with dihedral and vicinal angle, but must be contemplate as possible angle also increasing the unit from sets D, E or F, G.
2.3. Conic of Revolution and Dihedral Angle θHnHn+1[deg]
Cone of revolution, results from any Riemann surface of genus one embedded in the unit sphere S3CR4 as a flat torus, can be used for calculation the distances dHnHn+1i[A0] and bond length lCnCn+1[A0]. Distances between HnHn+1i can be calculated from rectangle geometry for cis stereochemistry and rhombus for trans stereochemistry with conic approach or from equilateral triangles having as based dHnHn+1i[A0]. In the light of distances demonstration on the conic approach, the bond lengths lCnCn+1[A0] for all stereochemistry are calculated with eq. 11. In case of rhombus geometry sin instead of cos give the required diagonal for trans-ee3,2 and trans-ee4,1.
Rectangle:
dHnHn+1i= 1.57xcos1/2θHnHn+1[A0](88)
Triangle:
dHnHn+1i= 0.5x[1.57xcos1/2HnHn+1/2)][A0] (9)
dHnHn+1i= 1.57xcos1/2(θ/2)[A0](10)
where: dHnHn+1i - distance between H1 and H2i in A0,
lCnCn+1= {1.54x[1.57xcos1/2HnHn+1/2)]}1/2[A0](11)
where θHnHn+1 – dihedral angles in deg.
3. Discussion
Dihedral angles θHnHn+1[deg] calculated from chemical shift δ [ppm] and vicinal coupling constant 3JHH[Hz] with 3-sphere approach are usefully for determination phase angle of pseudorotation P[deg] and angle of deviation from planarity θm[deg]. .
Dihedral angles θHnHn+1[deg] calculated with conic projection eq. (1)-(3) ensures the relationship between dihedral θHnHn+1[deg] and tetrahedral φ[deg] angles under sin and tan functions in opposite, a model for calculation used to date for five and six membered ring carbasugar. Higher number of units for choosing dihedral angle θHnHn+1[deg] with values almost equal with dihedral angle calculated only from recorded vicinal coupling constant have in opposite with tetrahedral φCn[deg] angles a complicatedly system for establishing the trigonometric equations. The main question, are dihedral and tetrahedral angles in opposite under strict sin and tan trigonometric functions for building units or simply relationships between sets A, B and D, E, and F, G ensure sin versus tan functions? Probably the conic projection manifold is the answer.
Conic projection as manifold proves that in case of radius of the cone inscribes on sphere at tangent point (r), calculated from height of cone h or inverse of height h-1, the tan function of h is equal with sin function of h-1 (Eq. (12)). .
60 - cos-1Rm= θAN1= sin-1r, θAI1= θAII1(12)
with N = I, II, n = 1 – 6.
A program for calculations dihedral θHnHn+1[deg] and tetrahedral φCn[deg] angles in opposite from sin and tan functions, can be simplified using first the trigonometric equations ensuring relationship between dihedral θHnHn+1[deg] and tetrahedral φCn[deg] on seven sets angle and six angles, and second can be chose in opposite dihedral θHnHn+1[deg] with tetrahedral φCn[deg] angles.
Euclidean coordinates in (n+1) space (Figure 4): 0-Sphere: pair of points (c-r, c+r), boundary of a line segment (1-ball); 1-Sphere: Abelian Lie grup structure U(1), circle group; 2-Sphere 3-dimensional Euclidean space (3-ball); 3-Sphere: also namely Glome, 4-dimension Euclidean space. Cylindrical coordinates having conic coordinates as limited case, surface of revolution with zero Gaussian curvature, giving the possibility to analyzed their geodesics on the equivalent flat surface are characteristic for torus. Unroll cone cut along a meridian become straight lines in the plane, and represent a way to translate in two-dimension. Conic projection versus conic section, as published already are coordinates used for hypersphere tessellation , a map projection that transform point from a sphere in tangent or secant of cone that is wrapped around the sphere .
Figure 4. Euclidian coordinates in (n+1) space.
From the trigonometric point of view vicinal ϕ[deg] angle is in close relationship with dihedral θHnHn+1[deg] angle on two sets angles, two intersecting circles, real Hopf fibration, relative to R4-complex Hopf fibration where both angles can be vicinal ϕ[deg] or dihedral θHnHn+1[deg] angles resulting two vicinal coupling constant 3JHH[Hz]. A hole inside of sphere gives two tori, topologically a ring torus is homeomorphic to the cartesian product of two circles T2 = S1xS1, a compact 2-manifold of genus 1. The transformation from sphere to torus simulate better by building unit S from trans-ee3,2 of unit U, and represent a good explanation for R16 octonionic Hopf fibration, double of quaternionic R7, for all cis, trans-ee, trans-aa stereochemistry, observed on two units representation with six sets angles or four sets angles from the strict trigonometric point of view. Since trigonometric equations don’t differentiate between trans-ee4,1 and trans-ee3,2, algebraic equations have different values and place angles on two units U and S with first angles higher or smaller as 5[deg]. .
Polyhedron equation under Fibonacci numbers Fn, golden ratio φ and golden triangle, can be used for transforming tetrahedral angles φCn[deg] presented in Table 2 from calculated angles in close relationships with dihedral angle, in predicted angles in agreement with five membered ring trigonometry, i.e. compound 2, φC2 104.94[deg] under polyhedron equation become 101.243[deg] and φC2 105.729[deg] under polyhedron equation become 106.796[deg]. Based on other conformational analysis on compound 2, in case of calculated phase angle of the pseudorotation E3 and E23T2 in close relationship with dihedral angles on seven sets angles, E3 conformation gives angles for C1,4 around 105 and for C2,3 around 104[deg] on seven sets angles. Calculated tetrahedral angles φCn[deg] can be considered transition states (TS), or only values result from six sets angles must be considered, polyhedron transformation giving values comparable with six sets angles. Since between E3 and E2 3T2 are not expected higher differences on values of tetrahedron angles, probably one from two methods must be applied as well as at list the values of tetrahedron angles to be in line with five membered ring geometry .
As observation on Table 2, dihedral angles 10-θH3H4[deg] with 3JHH 9.1[Hz] and trans-aa 146.9[deg] and trans-ee 61.53[deg] stereochemistry are calculated with positive sign from vicinal angle ϕ 331.3 or 331.5[deg], angles characteristic for L-stereochemistry, relative to 82.81[deg] with only one possible positive dihedral angle, but inexistent on first units. Second vicinal angle giving negative sign for D-stereochemistry.
Conic of revolution on calculation of the distances dHnHn+1i[A0] and bond length lCnCn+1[A0] gives the relationship between dihedral angle and cis, trans- stereochemistry on rectangle and equilateral triangle.
4. Conclusions
Dihedral angles θHnHn+1[deg] are calculated with conic projection as manifold from differences between two atoms of carbon ΔδCnCn+1[ppm] and vicinal coupling constant 3JHH[Hz], or for carbon chemical shift δCn[ppm] and vicinal coupling constant 3JHH[Hz] in close relationships with tetrahedral angles φCn[deg] on seven or six sets angles unit(s). In attempt to reduce the number of units calculated by hand, relative to units build through set C, in few cases units are constructed also from sets F and G. Probably a model for calculation all the possible dihedral angles with values almost equals with recorded that must be applied for calculation the number of units until the calculated angles are almost equals with angles on first unit. .
The relationships between dihedral θHnHn+1[deg] and tetrahedral φCn[deg] angles in opposite from the trigonometric point of view was demonstrated with conic projection.
Conic of revolution on calculation of the distances dHnHn+1i[A0] and bond length lCnCn+1[A0] with eq. 8-11 was point out.
Abbreviations

RMN data

Nuclear Magnetic Resonance Data

Conflicts of Interest
The authors have not conflicted of interest.
References
[1] U. Pinkall, Hopf tori in S3, Invent.math 1985, 81, 379.
[2] Udo Hertrich-Jeromin Bulletin (New Series) of the American Mathematical Society 2005, 42(4), 549, ISBN 0-521-53569-7.
[3] D. Bender, Quantum qravity, energy wave sphere, and the proton radius, European J. Appl. Sci. 2024, 1291),
[4] Chemistry Libre Texts: Deriving the de Broglie Wave length;
[5] Conic Projection:
[6] C. I. Mitan, E. Bartha, P. Filip, R. Moriarty, Nuclear Magnetic Resonance Spectroscopy - Recent Research and Applications, chapter book: Dihedral and tetrahedral angles of five and six membered ring calculated from NMR data with 3-Sphere approach, IntachOpen 2025
[7] C.-I. Mitan, E. Bartha, M.-T. Caproiu, C. Draghici, C. Deleanu, Petru Filip, Robert M. Moriarty, Dihedral angles and conic projection under wave motion, 10-15 November 2025, MedMolMed 2025, Chisinau, Republica Moldova,
[8] R. M. Moriarty, C. I. Mitan, N. Branza-Nichita, K. R. Phares, D. Parrish, exo-Imino to endo-iminocyclitol rearrangement. A general route to five membered antiviral azasugars, Org. Lett. 2006, 8, 3465;
[9] R. M. Moriarty, C.-I. Mitan, B. Gu, T. Block, Hypersphere and antiviral activity of three alkyl chain iminocyclitols with D and L ribitol stereochemistry, Am. J. Chem. Soc. 2023, 9(1), 9;
[10] C.-I. Mitan, E. Bartha, P. Filip, Relationships between tetrahedral and dihedral on hypersphere coordinates, Rev. Roum. Chim. 2023, 68(5-6), 261;
[11] C.-I. Mitan, E. Bartha, P. Filip, C. Draghici, M.-T. Caproiu, R. M. Moriarty, 3-Sphere dihedral angles under wave character of the NMR data with applications on conformational analysis, ACS Spring, San Diego march 23 – 27, CARB 623, ID 4175487;
[12] C.-I. Mitan, E. Bartha, C. Draghici, M.-T. Caproiu, P. Filip, R. M. Moriarty, Hopf fibration on relationship between dihedral angle θHnHn-1[deg] and Vicinal angle ϕ[deg], angles calculated from NMR data with 3-Sphere approach and Java Script, Sci. J. Chem, 2022, 10(1), 21;
[13] C.-I. Mitan, E. Bartha, P. Filip, V. Dragutan, I. Dragutan, C. Deleanu, C. Draghici, M.-T. Caproiu, R. M. Moriarty, 3-Spherical conformational insights into iminocyclitols with 1-α-D-ribose and 1-β-L-ribose stereochemistry under homotopic behaviour of nuclear magnetic resonance data, Sci. J. Chem 2026, accepted.
[14] N-Sphere, 3-Sphere – Glome – 4 Dimension:
[15] C.-I. Mitan, E. Bartha, P. Filip, C. Draghici, M.-T. Caproiu, R. M. Moriarty, Java Script program for calculation of dihedral angles with manifold equations, Sci. J. Chem, 2024, 12(3), 42;
[16] C.-I. Mitan, P. Filip, E. Bartha, C. Draghici, M.-T. Caproiu, R. M. Moriarty, Stereochemistry of cistrans vicinal coupling constant 3JHH[Hz] on 3-Sphere approach with application in conformational analysis, ACS Spring, San Diego march 23 – 27, Sci-Mix CARB – ANYL 632, ID 4175485;
[17] C.-I. Mitan, E. Bartha, P. Filip, Distances lHnHn+1[A0] calculated from 3-Sphere dihedral angles θHnHn+1[deg];
Cite This Article
  • APA Style

    Mitan, C., Bartha, E., Filip, P., Caproiu, M., Draghici, C., et al. (2026). Conic Projection as Manifold and 3-Sphere Dihedral Angles θHnHn+1[Deg] Under Homotopy. Science Journal of Chemistry, 14(1), 12-24. https://doi.org/10.11648/j.sjc.20261401.12

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    Mitan, C.; Bartha, E.; Filip, P.; Caproiu, M.; Draghici, C., et al. Conic Projection as Manifold and 3-Sphere Dihedral Angles θHnHn+1[Deg] Under Homotopy. Sci. J. Chem. 2026, 14(1), 12-24. doi: 10.11648/j.sjc.20261401.12

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    AMA Style

    Mitan C, Bartha E, Filip P, Caproiu M, Draghici C, et al. Conic Projection as Manifold and 3-Sphere Dihedral Angles θHnHn+1[Deg] Under Homotopy. Sci J Chem. 2026;14(1):12-24. doi: 10.11648/j.sjc.20261401.12

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  • @article{10.11648/j.sjc.20261401.12,
      author = {Carmen-Irena Mitan and Emerich Bartha and Petru Filip and Miron-Teodor Caproiu and Constantin Draghici and Calin Deleanu and Valeriu Dragutan and Robert Michael Moriarty},
      title = {Conic Projection as Manifold and 3-Sphere Dihedral Angles θHnHn+1[Deg] Under Homotopy},
      journal = {Science Journal of Chemistry},
      volume = {14},
      number = {1},
      pages = {12-24},
      doi = {10.11648/j.sjc.20261401.12},
      url = {https://doi.org/10.11648/j.sjc.20261401.12},
      eprint = {https://article.sciencepublishinggroup.com/pdf/10.11648.j.sjc.20261401.12},
      abstract = {Conic projection as manifold enable calculation dihedral θHnHn+1[deg] angles from differences between two atoms of carbon ΔδCnCn+1[ppm] in three steps or from only one atom of carbon δCn[ppm] in close relationships with tetrahedral φCn[deg] angles under 3-Sphere approach. Hopf fibration and Lie algebra ensuring calculation dihedral θHnHn+1[deg] angles from vicinal ϕ[deg] angle, angle results from vicinal coupling constant 3JHH[Hz]. Real Hopf fibration for calculation dihedral θHnHn+1[deg] angle in real space, and R16 octonionic Hopf fibration, double of quaternionic R7, for all cis, trans-ee, trans-aa stereochemistry, unreal space relative to calculated dihedral θHnHn+1[deg] angle. Continue “deformation”, homotopic behaviour h ⇆ h-1 characteristic for wave NMR data, probably a point of swich on Möbius band, in case of radius r of the cone inscribes on sphere at tangent point, calculated from height of cone h or inverse of height h-1, the tan function of h is equal with sin function of h-1. Dihedral θHnHn+1[deg] and tetrahedral φCn[deg] angles are from the trigonometric point of view under sin and tan function, or viceversa, homotopic behavior of NMR data under conic projection demonstrating that. Because the dihedral θHnHn+1[deg] angles are not found in first unit, for few vicinal coupling constants 3JHH[Hz], the rule accepted until now are explored taking in consideration other sets for building unit along the set C, respectively D, E and F, G, or vicinal angle ϕ[deg] with its three possible dihedral θHnHn+1[deg] angles in close relationships with tetrahedral φCn[deg] angles under seven sets unit. Building units through sets U or S calculated from sin or tan functions until calculated angles are almost equals with angles of unit U1 or S1, required long time for calculation.},
     year = {2026}
    }
    

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  • TY  - JOUR
    T1  - Conic Projection as Manifold and 3-Sphere Dihedral Angles θHnHn+1[Deg] Under Homotopy
    AU  - Carmen-Irena Mitan
    AU  - Emerich Bartha
    AU  - Petru Filip
    AU  - Miron-Teodor Caproiu
    AU  - Constantin Draghici
    AU  - Calin Deleanu
    AU  - Valeriu Dragutan
    AU  - Robert Michael Moriarty
    Y1  - 2026/02/26
    PY  - 2026
    N1  - https://doi.org/10.11648/j.sjc.20261401.12
    DO  - 10.11648/j.sjc.20261401.12
    T2  - Science Journal of Chemistry
    JF  - Science Journal of Chemistry
    JO  - Science Journal of Chemistry
    SP  - 12
    EP  - 24
    PB  - Science Publishing Group
    SN  - 2330-099X
    UR  - https://doi.org/10.11648/j.sjc.20261401.12
    AB  - Conic projection as manifold enable calculation dihedral θHnHn+1[deg] angles from differences between two atoms of carbon ΔδCnCn+1[ppm] in three steps or from only one atom of carbon δCn[ppm] in close relationships with tetrahedral φCn[deg] angles under 3-Sphere approach. Hopf fibration and Lie algebra ensuring calculation dihedral θHnHn+1[deg] angles from vicinal ϕ[deg] angle, angle results from vicinal coupling constant 3JHH[Hz]. Real Hopf fibration for calculation dihedral θHnHn+1[deg] angle in real space, and R16 octonionic Hopf fibration, double of quaternionic R7, for all cis, trans-ee, trans-aa stereochemistry, unreal space relative to calculated dihedral θHnHn+1[deg] angle. Continue “deformation”, homotopic behaviour h ⇆ h-1 characteristic for wave NMR data, probably a point of swich on Möbius band, in case of radius r of the cone inscribes on sphere at tangent point, calculated from height of cone h or inverse of height h-1, the tan function of h is equal with sin function of h-1. Dihedral θHnHn+1[deg] and tetrahedral φCn[deg] angles are from the trigonometric point of view under sin and tan function, or viceversa, homotopic behavior of NMR data under conic projection demonstrating that. Because the dihedral θHnHn+1[deg] angles are not found in first unit, for few vicinal coupling constants 3JHH[Hz], the rule accepted until now are explored taking in consideration other sets for building unit along the set C, respectively D, E and F, G, or vicinal angle ϕ[deg] with its three possible dihedral θHnHn+1[deg] angles in close relationships with tetrahedral φCn[deg] angles under seven sets unit. Building units through sets U or S calculated from sin or tan functions until calculated angles are almost equals with angles of unit U1 or S1, required long time for calculation.
    VL  - 14
    IS  - 1
    ER  - 

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Author Information
  • Department of Organic Chemistry, “C. D. Nenitescu” Institute of Organic and Supramolecular Chemistry of Romanian Academy, Bucharest, Romania

  • Department of Organic Chemistry, “C. D. Nenitescu” Institute of Organic and Supramolecular Chemistry of Romanian Academy, Bucharest, Romania

  • Department of Organic Chemistry, “C. D. Nenitescu” Institute of Organic and Supramolecular Chemistry of Romanian Academy, Bucharest, Romania

  • Department of Organic Chemistry, “C. D. Nenitescu” Institute of Organic and Supramolecular Chemistry of Romanian Academy, Bucharest, Romania

  • Department of Organic Chemistry, “C. D. Nenitescu” Institute of Organic and Supramolecular Chemistry of Romanian Academy, Bucharest, Romania

  • Department of Organic Chemistry, “C. D. Nenitescu” Institute of Organic and Supramolecular Chemistry of Romanian Academy, Bucharest, Romania

  • Department of Organic Chemistry, “C. D. Nenitescu” Institute of Organic and Supramolecular Chemistry of Romanian Academy, Bucharest, Romania

  • Department of Chemistry, University of Illinois at Chicago, Chicago, US