A modified synthesis of 1 α-hydroxyvitamin D3

Abstract

Base-catalysed deconjugation of cholesta-1,4,6-trien-3-one to cholesta-1,5,7-trien-3-one is a key step in a reported route to 1α-hydroxyvitamin D₃. A procedure for greatly improving the yield of the product, which allows its isolation via direct crystallisation, is reported. This procedure, used in conjunction with a recently described method for α-epoxidation of protected Δ¹-3β-ols, has been employed in a relatively efficient synthesis of 1α-hydroxyvitamin D₃.