Stereoselective Reactions of α-Imide Substituted Radicals

Article abstract of DOI:10.1016/S0040-4020(01)85232-7

The Barton esters 17 and 18, synthesized from the corresponding amino acid derivatives 6 and 14, were irradiated in situ with or without an external trap.Thus, thiopyridines 22 and 23, phenylselenides 24 and 25, esters 26 and 27 as well as deuterated products 34 and 35 were isolated when the radicals 20 and 21 were trapped with Barton esters 17 and 18 or with PhSeSePh, methyl acrylate or Bu3SnD.In all cases the anti isomers were isolated as the major products in moderate to excellent selectivity.The stereochemical course of the radical can be explained by the allylic strain model.