Reaction of trimethylsilylimidazole with 5,10β-epoxy-3-ketosteroids: Enolization and aromatization of the A-ring

Article abstract of DOI:10.1016/0039-128X(89)90150-5

The reaction of trimethylsilylimidazole (TSIM) and 3-keto-5,10-epoxy-nor-19-methylandrostanone 3 and its 17-acetate analog 4 was examined at two different temperatures.In both compounds, reaction at 90 deg C gave predominantly a Δ³-silyl-enol ether plus a minor product as a result of the epoxide ring opening.Under reflux conditions, besides the aforementioned products, aromatization of the A-ring was observed as a major process.The results suggest the potential use of silylation reactions with epoxyketones towards the synthesis of aromatic compounds.