Participation of a bridgehead thiiranium ion in the acid-catalysed disproportionation of 1,2,3,4-tetrahydro-8-methoxy-6H-dibenzo[b,d]thiopyran
Abstract
Acid-catalysed disproportionation of 1,2,3,4-tetrahydro-8-methoxy-6H-benzo[b,d]thiopyran gives two reduction products, both of which are derived from the intermediate bridgehead thiiranium ion.