Synthesis of polyhydroxysterols (V): efficient and stereospecific synthesis of 24-methylene-cholest-5-ene-3beta,7alpha-diol and its C-7 epimer.
This paper describes the efficient and stereospecific synthesis of cytotoxic dihydroxylated sterols, 24-methylene-cholest-5-ene-3beta,7alpha-diol 1, and its C-7 epimer, 24-methylene-cholest-5-ene-3beta,7beta-diol 2. The crux of the synthesis is that the selective allylic oxidation of 24-methylene-cholesteryl acetate proceeds to 24-methylene-7-keto-cholesteryl acetate without extensive byproduct formation from reaction at the Delta24(28) double bond. This methodology may be useful for the preparation of other oxysterols with non-standard side chains.
Lu
Weigang
W
School of Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou 510275, PR China.
Zhang
Cuixian
C
Zeng
Longmei
L
Su
Jingyu
J
D002777:Cholestanols / Q000138:chemical synthesis*; D002782:Cholestenes / Q000138:chemical synthesis*; D002788:Cholesterol Esters / Q000737:chemistry; D010084:Oxidation-Reduction; D013237:Stereoisomerism
C501868:24-methylenecholest-5-ene-3,7-diol; D002777:Cholestanols; D002782:Cholestenes; D002788:Cholesterol Esters; C060123:cholesterol acetate