NBS/DMSO-mediated synthesis of (2,3-dihydrobenzo[b][1,4]oxathiin-3-yl)methanols from aryloxymethylthiiranes

Abstract

(2,3-Dihydrobenzo[b][1,4]oxathiin-3-yl)methanols were synthesized via reactions of aryloxymethylthiiranes and N-bromosuccinimide (NBS) in DMSO under microwave irradiation. The reaction mechanism was proposed as an intramolecular aromatic electrophilic substitution of 1-bromo-2-(aryloxymethyl)thiiran-1-iums, generated from aryloxymethylthiiranes and NBS, and the subsequent DMSO nucleophilic ring opening reaction of thiiran-1-iums followed by the water displacement. The current method provides a direct and simple strategy in the efficient preparation of (2,3-dihydrobenzo[b][1,4]oxathiin-3-yl)methanols from readily available aryloxymethylthiiranes.