Enantiospecific Sn(Ⅱ)- and Sn(Ⅳ)-Catalyzed Cycloadditions of Aldehydes and Donor-Acceptor Cyclopropanes

摘要

We have developed the synthesis of 2, 5-disubstituted tetrahydrofurans in excellent yield, diastereoselectivity, and a very high degree of absolute stereochemical control from a formal cyclopropane/aldehyde cycloaddition. The tetrahydrofuran products can be further manipulated to allow for the preparation of more complex optically active heterocycles. This reaction is believed to proceed through an initial S_n2 attack on the activated cyclopropane, and through this process, absolute stereochemical information is transferred to the product.