title: Systematic synthesis of Bis-THF ring cores in annonaceous acetogenins.
abstract: Systematic synthesis of bis-THF ring cores, synthetic intermediates of adjacent bis-THF annonaceous acetogenins, has been achieved by asymmetric alkynylation and subsequent stereodivergent THF ring formation. The asymmetric alkynylation of alpha-tetrahydrofuranic aldehyde with (S)-3-butyne-1,2-diol derivatives gave good yields of erythro- and threo-adducts with very high diastereoselectivity. These adducts were converted into four types of bis-THF cores via two kinds of one-pot THF ring formation. [reaction: see text]
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: Naoto
authors.initials: N
authors.lastname: Kojima
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Tominaga
authors.forename: Minori
authors.initials: M
authors.lastname: Yanai
authors.forename: Tetsuaki
authors.initials: T
authors.lastname: Tanaka