Transannular brominolysis of 5,7,12,14-tetrahydrodibenzo [c,h][1,6] dithiecins by pyridinium hydrobromide perbromide

Abstract

A facile ring-opening reaction has been observed for 5,7,12,14-tetra hydrodibenzo[c,h][1,6]dithiecin (5) and 1,4,8,11-tetramethyl-5,7,12,14-tetrahydrodibenzo[c,h][1,6]dithiecin (6) on treatment with pyridinium hydrobromide perbromide. Compound (5) gave mainly bis(o-bromomethylbenzyl) disulphide (9) together with trace amounts of 1,2-bis(bromomethyl)benzene and 1,4-dihydro-2,3-benzodithiin (8). Similar products were isolated for compound (6). A reaction pathway involving the participation of the two transannular sulphur atoms in these systems is proposed.