Synthesis of 3,4,6,7-tetrahydro-1H-5,2-benzoxathionines by S-ylide rearrangement

Abstract

Substituted 3,4,6,7-tetrahydro-1H-5,2-benzoxathionines 4 have been synthesized by the base-assisted aromatization of [2,3] sigmatropic rearrangement products 7 (substituted 1,3,4,11a-tetrahydro-6H-5,2-benzoxathionines) of the S-ylides 3, which were generated by the reaction of trans-3-(substituted phenyl)-4-(trimethylsilyl)methyl-1,4-oxathianium perchlorate 2 with caesium fluoride in dimethyl sulfoxide (DMSO) at room temperature.