STEREOCONTROLLED SYNTHESIS OF 2,5-LINKED BISTETRAHYDROFURANS VIA THE TRIEPOXIDE CASCADE REACTION

Article abstract of DOI:10.1016/S0040-4020(01)90574-5

A complementary set of stereochemically controlled approaches to the preparation of twelve diastereomers of the bistetrahydrofurans 11 is described.The key transformation involves a series of nucleophilic displacement reactions within triepoxides 19 - the "end-to-end" triepoxide cascade reaction - which leads, presumably via 22 and 23, after acetylation to bistetrahydrofuran tetraacetates 24.The "inside-out cyclization of 30 exemplifies a useful variation with significant stereochemical consequences.The role of symmetry in these approaches is discussed.A general mathematical analysis for conceptualizing isomer distribution within multistep sequences is presented.