Synthetic applications of intramolecular insertion in arylcarbenes. VI. Ylid rearrangements in pyrolysis of o-alkylthiophenylcarbenes

Abstract

Low-pressure thermal generation of a range of o-alkylthiophenylcarbenes produces, in addition to the normal insertion products, styrenes and 1,3-dihydrobenzo[c]thiophens-clearly arising from rearrangement. The main features of their mechanism of formation are established by deuterium-labelling studies: in both cases participation by S-ylids is implicated.