Short, Enantioselective Total Synthesis of Aflatoxin B<sub>2</sub> Using an Asymmetric [3+2]-Cycloaddition Step
作者:Gang Zhou、E. J. Corey
DOI:10.1021/ja054503m
日期:2005.8.1
A highly enantioselective [3+2]-cycloaddition reaction of 2,3-dihydrofuran with 1,4-benzoquinones using a chiral oxazaborolidinium triflimidate as catalyst has been developed which allows rapid access to a variety of chiral phenolic tricycles (enantiomeric excesses ranging from 91 to 98%). The utility of this new methodology is demonstrated by a shortsynthesis of the important pentacyclic natural
Quinone Approaches toward the Synthesis of Aflatoxin B<sub>2</sub>
作者:Wayland E. Noland、Brant L. Kedrowski
DOI:10.1021/ol006014r
日期:2000.7.1
[reaction: see text] Quinones bearing electron-withdrawing groups can serve as useful precursors to furobenzofuran ring systems through their reaction with 2,3-dihydrofuran. Formal racemic and stereoselective syntheses of the fungal metabolite aflatoxin B(2) are described that utilize this approach to construct the tricyclic ABC-ring core of the molecule.