Abstract A simple one-pot process for in situ bromination of (ethoxycarbonylmethylene)-triphenylphosphorane 1 was carried out. This was followed by oxidation of alcohol using SO3. Pyridine complex as a mild oxidant and in situ trapping of the aldehyde. This process constitutes a stereoselective one-pot procedure for the preparation of Z-configured α-bromo-α, β-unsaturated esters in good yield. GRAPHICAL