One-Step Conversion of Ketones to Conjugated Acids Using Bromoform

Phase-transfer-catalyzed (PTC) reactions of ketones with bromoform and aqueous lithium hydroxide in alcoholic solvent result in the formation of alpha,beta-unsaturated carboxylic acids. The reaction was performed at room temperature for 24h. The corresponding conjugated acids were obtained from cyclic or aromatic ketones, whereas bromo acids were obtained from 4-oxo-piperidine-1-carboxylic acid ethyl ester (13) and 4-oxo-piperidine-1-carboxylic acid tert-butyl ester (14).