Reductive openings of benzylidene acetals revisited: a mechanistic scheme for regio- and stereoselectivity.
Despite the importance of regioselective reductive openings of cyclic acetals, mechanistic details are scarce. In this study 4,6-O-benzylidene acetals were used as model compounds for deciphering the mechanism of regioselective openings using a variety of reducing agents. Competitive isotopic studies aiming at primary and secondary isotope effects, as well as an electron-deficient substrate, were