Highly stereoselective synthesis of a seven-membered carbasugar via triisobutylaluminium promoted Claisen rearrangement

Abstract 2-Methylene-5-vinyl-tetrahydrofuran derivative 6 was obtained from α- d -glucose. Treatment of 6 with triisobutylaluminium (TIBAL) induced Claisen expansion reaction to give the seven-membered carbasugar derivative 7 , which represents a new type of chiral building blocks. The rearrangement reaction has been proved to be highly stereoselective.