A reliable preparative-scale synthesis of 1-bromo-1-lithioethene is reported. This reagent undergoes clean 1, 2-addition with a range of aldehydes and ketones at-105° C to afford the corresponding 2-bromo-1-alken-3-ols in moderate to excellent yield. Efficient diastereoselective addition to α-siloxy and α-methylcyclohexanones, as well as protected 3- keto furanose sugars, is achieved in the presence of 10 mol% CeBr3. The resulting ...