title: Systematic construction of a monotetrahydrofuran-ring library in annonaceous acetogenins by asymmetric alkynylation and stereodivergent tetrahydrofuran-ring formation.
abstract: All eight diastereoisomers of the monotetrahydrofuran-ring cores of annonaceous acetogenins have been synthesized through utilization of asymmetric alkynylation and stereodivergent one-pot tetrahydrofuran-ring formation. In all cases, the asymmetric alkynylation proceeded with very high diastereoselectivity to give eight kinds of optically pure tetrahydrofuran core from a common alpha-oxyaldehyde. We also describe a comparison of the (1)H NMR, (13)C NMR, and CD spectral data of the eight isomers and give full details of the tetrahydrofuran-ring construction including a model study of asymmetric alkynylation.
authors.affiliation: Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan.
authors.forename: Naoto
authors.initials: N
authors.lastname: Kojima
authors.forename: Naoyoshi
authors.initials: N
authors.lastname: Maezaki
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Tominaga
authors.forename: Mikito
authors.initials: M
authors.lastname: Asai
authors.forename: Minori
authors.initials: M
authors.lastname: Yanai
authors.forename: Tetsuaki
authors.initials: T
authors.lastname: Tanaka