Diastereoselective Rh-Mediated Construction of 2,3,5-Trisubstituted Tetrahydrofurans

Abstract

Dirhodium(II) carboxylate catalyzed cyclization of a series of γ-alkoxy-α-diazo esters 1 has been shown to proceed with substantial diastereoselectivity, producing the 2,3,5-trisubstituted tetrahydrofurans 2 and 3. The diastereoselectivity of the cyclization improved as the electron-withdrawing ability of the substituent R increased. A mechanistic hypothesis is presented