REVERSAL OF PI-FACE SELECTIVITY IN THE EVANS ALDOL REACTION WITH FLUORAL - A COMPUTATIONAL STUDY ON THE TRANSITION-STATES USING SEMIEMPIRICAL CALCULATIONS
Y. Makino et al., REVERSAL OF PI-FACE SELECTIVITY IN THE EVANS ALDOL REACTION WITH FLUORAL - A COMPUTATIONAL STUDY ON THE TRANSITION-STATES USING SEMIEMPIRICAL CALCULATIONS, Tetrahedron letters, 36(36), 1995, pp. 6527-6530
Transition states for aldol reactions of boron enolate derived from N-
acyloxazolidinone with acetaldehyde and fluoral were located by semiem
pirical molecular orbital calculation. For reaction with acetaldehyde,
a chair transition structure was found, while two open transition str
uctures were obtained with fluoral. The transition states reproduced t
he experimental results such that acetaldehyde and fluoral react prefe
rentially on the re and si faces of the double bond of the boron enola
te.