Reaction of S-benzyl-substituted sulfonium ylids of dimedon with triphenylphosphine and tris(dimethylamino)phosphine

1. S-Benzyl-substituted sulfonium ylids of dimedon are dealkylated by triphenylphosphine and tris(dimethylamino) phosphine to give phosphonium salts that are stabilized by etiolate anion. 2. Migration of the phenyl group to the phosphorus atom is not observed when 2-benzylphenylsulfuranylidenedimedon is reacted with triphenylphosphine or tris(dimethylamino)phosphine. In the case of 2-benzyl-methylsulfuranylidenedimedon the migration of the benzyl group is predominant in the reaction with triphenyl-phosphine, while only the methyl group migrates in the reaction with tris(dimethylamino)phosphine. © 1978 Plenum Publishing Corporation