Synthesis of polyhydroxysterols (III): synthesis and structural elucidation of 24-methylenecholest-4-en-3beta,6 alpha-diol.
Using stigmasterol as the starting material, 24-methylenecholest-4-en-3beta,6 alpha-diol (2) was synthesized in eight steps in 13% overall yield. The introduction of the sterol side-chain was carried out using (3-methyl-2-oxobutyl)-triphenylarsonium bromide (11) and K(2)CO(3) in a solid-liquid phase-transfer Wittig reaction. Construction of the steroidal nucleus was finished by oxidation of 24-methylenecholest-5-en-3beta-ol (9) with pyridinium chlorochromate (PCC) in dichloromethane at ambient temperature and by reduction of 24-methylenecholest-4-en-3,6-dione (10) with NaBH(4) in the presence of CeCl(3).7H(2)O.
Cui
Jian Guo
JG
Department of Chemistry, Zhongshan University, Guangzhou 510275, PR China. cuijg@public.nn.gx.cn
Lin
Cui Wu
CW
Zeng
Long Mei
LM
Su
Jing Yu
JY
D002776:Cholestanes / Q000138:chemical synthesis* / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D013261:Sterols / Q000138:chemical synthesis* / Q000737:chemistry*; D013265:Stigmasterol / Q000737:chemistry
C093891:24-methylenecholest-4-ene-3,6-diol; D002776:Cholestanes; D013261:Sterols; D013265:Stigmasterol