Catalytic Asymmetric Total Synthesis of Schibitubin G and Revision of Its Absolute Configuration
Xi Tang1, Xian-Bin Tang1, Chu-Xuan Yan1
1School of Chemistry, Southwest Jiaotong University, Chengdu 610031, P. R. China.
Abstract:
The first total syntheses of dibenzylbutane-type lignan shibitubin G, and of its enantiomer, were achieved from commercially available vanillin. A key catalytic asymmetric Michael addition reaction was used to introduce the C8' chiral center of this natural product. The absolute configuration of natural schibitubin G was revised to 8'S based on the X-ray crystallographic analysis of 14, and by comparing optical rotations of both synthetic samples with that of natural schibitubin G.
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