Azasteroids. Part III. The synthesis of 8-aza-19-norprogesterone

Abstract

The title compound and its 18-methyl homologue have been synthesised from the corresponding 8-azaoestrone 3-methyl ether. Key steps are a Wittig reaction to give the appropriate 17-ethylidene compound followed by hydroboration to incorporate the C-20-oxygen function. The stereochemistry of the intermediates is discussed. A convenient oxidation of 8-azaoestrone 3-methyl ether to the corresponding Δ⁹⁽¹¹⁾-enamine is also described.