title: Stereodivergent and reiterative synthesis of bistetrahydrofuran ring cores of annonaceous acetogenins.
abstract: Eight diastereoisomers of the bistetrahydrofuran ring cores of annonaceous acetogenins have been synthesized by asymmetric alkynylation of alpha-tetrahydrofuranic aldehydes and stereodivergent one-pot tetrahydrofuran (THF) ring formation. In all cases, the asymmetric alkynylation proceeded with very high diastereoselectivity to give eight kinds of optically pure THF cores. We also describe a comparison of the (1)H and (13)C NMR spectral data of the eight isomers and give full details of the THF ring construction.
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: Minori
authors.initials: M
authors.lastname: Yanai
authors.forename: Daisuke
authors.initials: D
authors.lastname: Urabe
authors.forename: Tetsuaki
authors.initials: T
authors.lastname: Tanaka