Has been used to protect diols as their cyclic acetals, by azeotroping in the presence of TsOH: J. Am. Chem. Soc., 84, 430 (1962). The products are readily hydrolyzed by acid but are stable to hydrogenolysis conditions (Raney Ni) used to cleave O-benzyl groups: Tetrahedron, 42, 3021 (1986).