Transformations of steroidal neopentyl systems. Part IV. Stereochemistry of products of reaction of methyl-lithium with Δ5-19-aldehydes

Abstract

The reaction of methyl-lithium with 3β,17β-diacetoxyandrost-5-en-19-al and certain transformations of the derived products have been studied. Only the 19R-alcohol was formed by this reaction and its stereochemistry was proved through transformation into 17β-acetoxy-3α-methoxy-19-methyl-5α-androstane 3,19-oxide (9d). A reduction–oxidation reaction involving a 1,5-hydride ion transfer was observed during ethylene dioxide formation.