A New Method for the Stereoselective Synthesis of Macrodiolides From TADDOL Derivatives

Abstract

In previous studies, we reported the stereoselective radical addition of organotin hydrides to unsaturated TADDOL diesters. These reactions occurred with intramolecular cyclization under inert atmosphere, radical initiator, toluene and 75°C with high yields and stereoselectivity depending on the reactivity and steric bulk of the organotin hydride employed. 1 Here, we decided to study a new method for the synthesis of these macrocycles through the radical addition of different triorganotin hydrides, R 3 SnH (R= Me, n-Bu, Ph; Neophyl), to the same unsaturated TADDOL diesters, in THF as solvent and under MW conditions. We compared these results with the previous reported method. 1 Under MW conditions, reactions were completed in very short time and neither the double hydrostannation nor the cyclopolymerization products were obtained in both cases. Furthermore, we evaluated the stereoselectivity by 119 Sn-NMR spectroscopic analysis in both methods.