A neighboring group participation strategy: direct and highly diastereoselective synthesis of 2-substituted and 2,2-bisubstituted perhydrofuro[2,3-b]pyran derivatives
A highly diastereoselective synthesis method for 2-substituted and 2,2-bisubstituted perhydrofuro[2,3-b]pyran derivatives from 2-C-branched sugars via a neighboring group participation strategy was developed.
An effective and facile method for the synthesis of 2,2-di-substituted perhydrofuro[2,3-b]pyran (and furan) derivatives is described. The cyclization of 1,2-cyclopropanated sugars with olefins in the presence of BiCl3 is highly diastereoselective. 2,2-Di-substituted cyclization products were obtained in good to excellent yields.