A stable intermediate in the Sommelet–Hauser rearrangement of 1-methyl-2-phenyl-piperidinium 1-methylides: the improved Sommelet–Hauser rearrangement

Abstract

Reaction of 1-methyl-1-(trimethylsilyl)methyl-2-(substituted phenyl)piperidinium iodides (2) with caesium fluoride gave high yields of 2-methyl-1,3,4,5,6,11a-hexahydro-2H-2-benzazonines (4) which are regarded as unstable intermediates in the Sommelet-Hauser rearrangement of ammonium ylides (3) to 2-methyl-2,3,4,5,6,7-hexahydro-1H-2-benzazonine derivatives (5).