3beta,24-Bis(tert-butyldimethylsilyloxy)-4,4-dimethylchola-5,7-diene → 4,4-Dimethyl-5alpha-chola-8,14-dien-3beta,24-diol

HRID 1816488Notes

Reaction equation

HRID 1816488 reaction equation
[Si]([O:8][C@H:9]1[CH2:38][CH2:37][C@@:36]2([CH3:39])[C:11](=[CH:12][CH:13]=[C:14]3[C@@H:35]2[CH2:34][CH2:33][C@@:32]2([CH3:40])[C@H:15]3[CH2:16][CH2:17][C@@H:18]2[C@H:19]([CH3:31])[CH2:20][CH2:21][CH2:22][O:23][Si](C(C)(C)C)(C)C)[C:10]1([CH3:42])[CH3:41])(C(C)(C)C)(C)C>C(O)C.C1C=CC=CC=1.Cl>[CH3:42][C:10]1([CH3:41])[C@@H:9]([OH:8])[CH2:38][CH2:37][C@@:36]2([CH3:39])[C@H:11]1[CH2:12][CH2:13][C:14]1[C:15]3[C@:32]([CH3:40])([CH2:33][CH2:34][C:35]=12)[C@@H:18]([C@H:19]([CH3:31])[CH2:20][CH2:21][CH2:22][OH:23])[CH2:17][CH:16]=3

Participants

5

Reactant 1

HCID 694129983beta,24-Bis(tert-butyldimethylsilyloxy)-4,4-dimethylchola-5,7-diene

Product 1

HCID 155430924,4-Dimethyl-5alpha-chola-8,14-dien-3beta,24-diolYield 71.4%

Reagents, catalysts & solvents 3

HCID 241BenzeneSolventHCID 313Hydrochloric AcidSolventHCID 702EthanolSolvent

Procedure

A mixture of 3β,24-bis(tert-butyldimethylsilyloxy)-4,4-dimethylchola-5,7-diene (18.8 g) in 99.9% ethanol (375 ml), benzene (55 ml) and concentrated hydrochloric acid (55 ml) is heated to reflux for 4 hours. After standing overnight at room temperature, the reaction mixture is concentrated under reduced pressure. Crystallization of the remanens from ethanol/water gives 8.44 g of the title compound. Melting point: 203-208° C. 1H-NMR (CDCl3, 400 MHz): δ=5.36 (1H, s); 3.62 (2H, m); 3.23 (1H, m).

Workup

  1. temperatureis heated
  2. temperatureto reflux for 4 hours
  3. concentrationthe reaction mixture is concentrated under reduced pressure
  4. customCrystallization of the remanens from ethanol/water

Sources & evidence

ORD record
ord-019bdc63f26d4c8cb06292d72c6f4afd
Source dataset
uspto-grants-2005_04
Patent number
US06884796B2

Reaction notes

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