Triorganotin hydride reduction of 6β-isothiocyanatopenicillanates: a radical-induced sulphur–C(2) bond cleavage

Abstract

Triorganotin hydride reduction of methyl 6β-isothiocyanatopenicillanate is accompanied by intra-molecular radical capture and cleavage of the sulphur–C(2) bond to give thiazolines (9) and (10); a similar mechanism is proposed for the formation of thiazoline (3), a minor product of tri-n-butyltin hydride reduction of benzyl 6α-(1-hydroxyl-1-methylethyl)-6β-isocyanopenicillanate (1; R²= Me₂COH).