title: Asymmetric intramolecular michael addition of alpha-sulfinyl vinylic carbanion to enoates.
abstract: The first example of an asymmetric intramolecular Michael addition reaction with use of alpha-lithiated vinylic sulfoxide as a Michael donor is reported. Michael addition of the alpha-lithiated vinylic sulfoxide to (Z)-enoates proceeds with high diastereoselectivity to give the adducts with (R)-configuration at the beta-position of the ester in the five-membered-ring formation. The selectivity was reversed in the six-membered-ring formation. The resulting ester enolates were reacted with alkyl halides or benzaldehyde with high diastereoselectivity.
authors.affiliation: Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan.
authors.forename: Naoyoshi
authors.initials: N
authors.lastname: Maezaki
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Sawamoto
authors.forename: Sachiko
authors.initials: S
authors.lastname: Yuyama
authors.forename: Ryoko
authors.initials: R
authors.lastname: Yoshigami
authors.forename: Tomoko
authors.initials: T
authors.lastname: Suzuki
authors.forename: Mayuko
authors.initials: M
authors.lastname: Izumi
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Ohishi
authors.forename: Tetsuaki
authors.initials: T
authors.lastname: Tanaka