Abstract
A method for differentiating allylic diastereofaces of carbon-carbon double bonds has been developed based on the ground state molecular design of allylic compounds in which a protected vicinal (S, S) - or (R, R) -diol unit is incorporated as a controller. The protected vicinal diol groups, if they are the most bulky substituents, should arrange anti to each other and the remaining medium-sized groups involving the allylic carbon-carbon double bonds, for instance, stay gauche accordingly. This situation allows only a pair of diastereofaces exposed outside to be attacked by external reagents because a remaining pair of diastereofaces is mutually shielded from intermolecular processes. Such diastereo-bias has been successfully and diversely employed in diastereoselective processes such as double Michael reaction, osmium tetraoxide-catalyzed vicinal hydroxylation, halo-etherification, and Diels-Alder reaction, giving rise to exceptionally high diastereomeric excess for every case examined, appealing prospect for wide applicability in selective organic syntheses.
