Efficient Formation and Cleavage of Benzylidene Acetals by Sodium �Hydrogen Sulfate Supported on Silica Gel.

NaHSO4�SiO2 was used as an efficient heterogeneous catalyst for both the formation and the cleavage of benzylidene �acetals. This catalyst is compatible with many functional or protective groups. Under different solvent systems, either the formation or the cleavage of benzylidene acetals was carried out smoothly in �excellent yields and with good chemoselectivity. [ABSTRACT FROM AUTHOR]