A Formal Synthesis of Betamethasone. Issue 6 (2nd June 2015)

• Record Type: Journal Article
• Authors: Wang, Shasha; Shi, Yong; Tian, Weisheng
• Is Part Of: Chinese journal of chemistry. Volume 33:Issue 6(2015:Jun.)
• Page Start: 637
• Page End: 642
• Publication Date: 2015-06-02
• Subjects: betamethasone -- pregnanetriol -- formal synthesis -- C16β‐alkyl group -- double epoxidation; Chemistry -- Periodicals; 540.5
• DOI: 10.1002/cjoc.201500335
• Languages: English
• ISSNs: 1001-604X

Abstract

Abstract: A formal synthesis of betamethasone from 5 α ‐pregnane‐3 β, 16 β, 20 S ‐triol is described. Key transformations are a bromination‐acetylation of triol, an SN 2 reaction of the resulting C16 α ‐bromide with dimethylcopperlithium to get the required C16 β ‐methyl group, and a double hydroxylation to prepare the dihydroxyacetone side chain. Abstract : A formal synthesis of betamethasone from pregnane‐3 β, 16 β, 20 S ‐triol is described. Key transformations are a bromination‐acetylation of triol, an SN 2 reaction of the resulting C16 α ‐bromide with dimethylcopperlithium to get the required C16 β ‐methyl group, and a double hydroxylation to prepare the dihydroxyacetone side chain.