Simple diastereoselectivity of the BF3.OEt2-catalyzed vinylogous Mukaiyama aldol reaction of 2-(trimethylsiloxy)furans with aldehydes.
[reaction: see text] A comprehensive scan of the transition state space for the reaction of 2-(trimethylsiloxy)furan and methacrolein (24 combinations) offered a satisfactory explanation of the high like diastereoselectivity obtained experimentally in the Mukaiyama vinylogous aldol reaction of these and related partners. It was determined that the syn-gamma-hydroxyalkylbutenolides are formed preferentially following a g(+) orientation of the two reactants with the aldehyde in the s-trans conformation. Diastereoselectivity is shown to be caused by a combination of subtle effects favoring the formation of the like product.
López
Carlos Silva
CS
Departamento de Química Orgánica, Universidade de Vigo, Lagoas-Marcosende, 36310 Vigo, Galicia, Spain.
Alvarez
Rosana
R
Vaz
Belén
B
Faza
Olalla Nieto
ON
de Lera
Angel R
AR