title: Switching of product's chirality in diastereodifferentiating [2+2] photocycloaddition of (E)- versus (Z)-stilbene to chiral fumarate upon direct and charge-transfer-band excitation.
abstract: [reaction: see text] Diastereodifferentiating [2+2] photocycloadditions of (E)- and (Z)-stilbenes to bis((R)-1-methylpropyl) fumarate were performed through the direct excitation of stilbenes and the selective excitation of the charge-transfer (CT) complex at various temperatures. The geometrical isomers of stilbene afforded the opposite diastereomers of mu-truxinate in both excitation modes, with a dramatic decrease in the product's diastereoselectivity upon prolonged irradiations.
authors.affiliation: Department of Applied Chemistry, Osaka University, 2-1 Yamada-oka, Suita 565-0871, Japan.
authors.forename: Hideaki
authors.initials: H
authors.lastname: Saito
authors.forename: Tadashi
authors.initials: T
authors.lastname: Mori
authors.forename: Takehiko
authors.initials: T
authors.lastname: Wada
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Inoue