Epoxidation and reduction of cholesterol, 1,4,6-cholestatrien-3-one and 4,6-cholestadien-3beta-ol.
Many naturally occurring polyhydroxylated sterols and oxysterols exhibit potent biologic activities. This paper describes reagent and position selectivity of epoxidation and reduction of cholesterol derivatives. Cholesterol was reacted with m-chloroperoxybenzoic acid (m-CPBA) to form 5alpha,6alpha-epoxycholestan-3beta-ol, but in reaction with 30% H(2)O(2), it did not reacted. 1,4,6-cholestatrien-3-one was obtained from cholesterol and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone in dioxane. 1,4,6-cholestatrien-3-one was reacted with 30% H(2)O(2) and 5% NaOH in methanol to give 1alpha,2alpha-epoxy-4,6-cholestadien-3-one, which was stereoselectively reduced with NaBH(4) to form 1alpha,2alpha-epoxy-4,6-cholestadien-3beta-ol and reduced with Li metal in absolute ethanol to give 2-ethoxy-1,4,6-cholestatrien-3-one. And 1,4,6-cholestatrien-3-one was epoxidized with m-CPBA in dichloromethane to afford 6alpha,7alpha-epoxy-1,4-cholestadien-3-one, which was reacted with NaBH(4) to synthesize 6alpha-hydroxy-4-cholesten-3-one and reduced Li metal in absolute ethanol to form 2-ethoxy-1,4,6-cholestatrien-3-one, respectively. 1,4,6-cholestatrien-3-one was reduced with NaBH(4) in absolute ethanol to form 4,6-cholestadien-3beta-ol, which was reacted with 30% H(2)O(2) to leave original compound, but was reacted with m-CPBA to give 4beta,5beta-epoxy-6-cholesten-3beta-ol as the major product and 4beta,5beta-epoxy-6alpha,7alpha-epoxycholestan-3beta-ol as the minor product.
Ma
Eunsook
E
College of Pharmacy, Catholic University of Daegu, 330 Geumrak 1-ri, Hayang-eup, Gyongsan-si Gyongbook 712-702, Korea. masook@cu.ac.kr
Kim
Haksoon
H
Kim
Eunjeong
E
D001896:Boron Compounds / Q000737:chemistry; D002723:Chlorobenzoates / Q000737:chemistry; D002775:Cholestadienols / Q000737:chemistry*; D002782:Cholestenes / Q000737:chemistry*; D002784:Cholesterol / Q000737:chemistry*; D006861:Hydrogen Peroxide / Q000737:chemistry; D008094:Lithium / Q000737:chemistry; D015394:Molecular Structure; D010084:Oxidation-Reduction
D001896:Boron Compounds; D002723:Chlorobenzoates; D002775:Cholestadienols; D002782:Cholestenes; D002784:Cholesterol; D008094:Lithium; D006861:Hydrogen Peroxide; C000433:3-chloroperbenzoic acid