Regioselective etherification of l,2-O-isopropylidene-4,6-di-O-benzyl myo-inositol

During the etherification of 1,2-O-isopropylidene-4,6-di-O-benzyl myo-inositol, the specific regioselectivity on 3- or 5-hydroxyl group was showed to be determined by the nature of the O- alkylating agents used. As demonstrated by MM and MNDO calculation, the regioselectivity of the reaction mentioned can be rationalized by steric and/or electronic effect.