Stereodivergent and reiterative synthesis of bistetrahydrofuran ring cores of annonaceous acetogenins.
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.
Kojima
Naoto
N
Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan.
Maezaki
Naoyoshi
N
Tominaga
Hiroaki
H
Yanai
Minori
M
Urabe
Daisuke
D
Tanaka
Tetsuaki
T