β-Trimethylsilyl enol ethers 1 (Z) obtained from β-bromoenolethers 2 were condensed with aliphatic and aromatic aldehydes in the presence of a catalytic quantity of trimethylsilyl triflate leading to ethylenic aldehydes 3 (E) with good yields (79–90%).
α-Trimethylsilyl and α-triethylsilyl aldehydes 6 were obtained from trimethylsilyl and triethylsilyl β-bromo enol ethers 1, using a bromineâlithium exchange and a 1â3 migration of the trialkylsilyl group.