Regioselective ring opening of benzylidene acetals is one of the major challenges in carbohydrate and natural product syntheses.[1] Substituted and unsubstituted benzylidene acetals are valuable protecting groups to block 1, 3-diols. Arylidene acetals 1 can be opened selectively under appropriate reaction conditions (Scheme 1) to yield primary 2 (path a) or secondary alcohols 3 (path b). A number of effective reagents have been ...
