Kazuhisa Fujii

Reversal of π-face selectivity in the Evans aldol reaction with fluoral: A computational study on the transition states using semiempirical calculations

Abstract Transition states for aldol reactions of boron enolate derived from N -acyloxazolidinone with acetaldehyde and fluoral were located by semiempirical molecular orbital calculation. For reaction with acetaldehyde, a chair transition structure was found, while two open transition structures were obtained with fluoral. The transition states reproduced the experimental results such that acetaldehyde and fluoral react preferentially on the re and si faces of the double bond of the boron enolate.