Systematic synthesis of Bis-THF ring cores in annonaceous acetogenins.
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]
Maezaki
Naoyoshi
N
Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan.
Kojima
Naoto
N
Tominaga
Hiroaki
H
Yanai
Minori
M
Tanaka
Tetsuaki
T