Preparation and reactions of α,β-unsaturated and cross-conjugated diene thiones

Abstract

Δ^1,4-Diene-3-thiones were prepared from corticosterone-1,4-dien-3-ones and phosphorus pentasulphide. Reaction-with diphenyldiazomethane or 2-nitrobenzenesulphenyl chloride gave respectively the derived 3-diphenylmethylene-Δ^1,5-dienes and 3-(2-nitrobenzenesulphenylthio)-Δ^1,3,5-trienes. The less stable steroid Δ⁴-ene-3-thiones were trapped with 2-nitrobenzenesulphenyl chloride as 3-(2-nitrobenzenesulphenylthio)-Δ^3,5-dienes. Subsequent thiol exchange gave 3-ethane- and 3-benzene-sulphenylthio-Δ^3,5-dienes. Warfarin and cyclocumarol were thionated with P₄S₁₀ giving mono- and dithio-derivatives. Griseofulvin gave a stable enethione and thence with diphenyldiazomethane the diphenylmethylene derivative.