A practical and efficient procedure for the cleavage of acylals to aldehydes catalyzed by indium tribromide in water

Indium tribromide (10 mol %) is an efficient catalyst for chemoselective cleavage of aryl acylals in refluxing water. A variety of acylals have been deprotected to give the corresponding parent aldehydes in high yield. The procedure presented is operationally simple, practical, and compatible with other sensitive functionalities such as methoxy, methyleneioxy, and benzyloxy groups present in the substrates.