Some steroid heterocycles via enamines

Abstract

Reactions of steroid enamines with suitably substituted aromatic aldehydes have been used to synthesize steroid derivatives with a heterocyclic system joined to C-2 and C-3. Enamines from 3-keto-steroids and o-hydroxybenzaldehydes yield steroid adducts which contain the fused benzopyran nucleus. Similarly, o-aminobenzaldehyde reacts with steroid enamines to yield the corresponding quinoline derivatives. Aromatic compounds containing other carbonyl functions such as a ketone or an ester group do not produce these heterocycles. The o.r.d. spectra of the nitrogen heterocycles show a positive Cotton effect, whereas those of the oxygen heteroxycles show a negative Cotton effect.