Study of the mechanism of base induced dehydrobromination of trans-β-bromostyrene

Observation that rates of dehydrobromination of trans-β-bromostyrene () and the Hofmann degradation of tetrabutyl ammonium cation depend on strength of base in different ways and that treatment of with base results in fast abstraction of the β-proton imply the possibility that the dehydrobromination of could proceed via α-elimination and Ph migration. In order to clarify this question, β-13C-labeled was obtained and subjected to PTC dehydrobromination which proceeds without migration of Ph. The obtained results are consistent with an irreversible E1cB mechanism.