Supposed acetyl migration from the 3β- to the 19-hydroxyl group in Δ⁵-steroids

Abstract

The product of monotritylation of 3β,19-dihydroxyandrost-5-en-17-one is the 3β-trityl ether, not the 19-trityl ether as previously proposed. In consequence the product of acetylation of the monotrityl ether is 19-acetoxy-3β-trityloxyandrost-5-en-17-one and thus acid-catalysed detritylation of this compound yields directly the 19-acetoxy derivative without the invoking of an acid-catalysed rearrangement. The isomeric 3β-hydroxy-19-trityloxyandrost-5-en-17-one has been prepared as well as a number of 3β-tritylated Δ⁵-steroids which have been used to study the influence of the trityl ether group upon p.m.r. chemical shifts in this series.