Pregnenolone acetate synthesis
- Product Name:Pregnenolone acetate
- CAS Number:1778-02-5
- Molecular formula:C23H34O3
- Molecular Weight:358.51
145-13-1
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75-36-5
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1778-02-5
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Yield:1778-02-5 99.6 %
Reaction Conditions:
with pyridine in dichloromethane at 0 - 20;
Steps:
3β-Acetoxypregn-5-en-20-one (3)
To a cooled suspension of pregnenolone (2) (50.0 g, 0.158 mol), pyridine (15.4 g,0.195 mol) in 400 ml anhydrous DCM, acetyl chloride (13.7 g, 0.176 mol) was added dropwise at 0 C over 10 min, after that, the resulting mixture was allowed to warm to room temperature and stirred for 3 h. Water (300 ml) was added, and then the organic layer was separated and washed with brine (100 ml) and water (100 ml), dried over Na2SO4. Evaporation of the solvent under vacuum afforded the white solid 3 (56.4 g) in 99.6% yield, mp 142-145 C. 1H-NMR (CDCl3, 500 MHz): d 0.64 (s, 3H,18-Me), 1.02 (s, 3H, 19-Me), 1.13-1.28 (m, 3H), 1.43-1.73 (m, 9H), 1.88 (d,J10.0 Hz, 2H), 1.99-2.03 (m, 1H), 2.04 (s, 3H, 3b-OAc), 2.05-2.07 (m, 1H), 2.13 (s,3H, 21-Me), 2.15-2.22 (m, 1H), 2.32-2.34 (m, 2H), 2.52-2.56 (m, 1H), 4.61 (m, 1H,C3-Ha), 5.39 (d, J5.0 Hz, 1H, C6-H). 13C-NMR (CDCl3, 125 MHz): d 13.2, 19.3,21.0, 21.4, 22.8, 24.5, 27.7, 31.6, 31.8, 31.8, 36.6, 37.0, 38.1, 38.8, 44.0, 49.9, 56.8, 63.7,73.8, 122.3, 139.7, 170.5, 209.5. HRESIMS: m/z 381.2403 [MNa] (calcd for C23H34O3Na, 381.2406).
References:
Wang, Yan;Dong, Wei;Zhang, Qin;Li, Zhen-Peng;Wang, Yue-Xing;Li, Xiu-Fen;Huang, Long-Jiang [Journal of Asian Natural Products Research,2022]
979-02-2
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1778-02-5
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$12.00/1mg
145-13-1
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$28.00/500mg
108-24-7
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$14.00/250ML
1778-02-5
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$12.00/1mg
17916-30-2
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1778-02-5
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76984-91-3
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1778-02-5
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