On the synergism between H2O and a tetrahydropyran template in the regioselective cyclization of an epoxy alcohol.

ABSTRACT: A regioselective epoxy alcohol cyclization promoted by the combination of neutral water and a tetrahydropyran template was investigated through a series of mechanistic experiments carried out on an epoxy alcohol containing a tetrahydropyran ring (1a) and its carbocyclic congener (1b). In contrast to 1a, cyclizations of 1b were unselective and displayed significantly faster reaction rates suggesting that the tetrahydropyran oxygen in 1a is requisite for regioselective cyclization. Reactions for both substrates were shown to occur in solution and under kinetic control without significant influence from hydrophobic effects. Kinetic measurements carried out in water/dimethyl sulfoxide mixtures suggest that 1b reacts exclusively through an unselective pathway requiring one water molecule more t

SUBMITTER: Byers JA 

PROVIDER: S-EPMC2803756 | biostudies-literature | 2009 May

REPOSITORIES: biostudies-literature