Regiospecific Formal [3+2] Annulations of α‐keto Sulfines and N‐Substituted Thioureas

Abstract

AbstractA series of 2,4‐dithiohydantoins were synthesized regiospecificlly from various phenacyl sulfoxides bearing 1‐methyl‐1H‐tetrazole and N‐substituted thioureas in moderate to excellent yields. The proposed mechanism involved the generation of α‐sulfines from sulfoxides through thermolytic elimination, carbonphilic attack of sulfines by substituted thioureas, and dehydration condensation. The current method provides a safe strategy for the preparation of 2,4‐dithiohydantoins.