Thermodynamically driven: Syn -selective vinylogous aldol reaction of tetronamides

A stereoselective vinylogous aldol reaction of N-monosubstituted tetronamides with aldehydes is described. The procedure is simple and scalable, works well with both aromatic and aliphatic aldehydes, and affords mainly the corresponding syn-aldol adducts. In many cases, the latter are obtained essentially free of their anti-isomers (dr > 99:1) in high yields (70-90%). Experimental and computational studies suggest that the observed diastereoselectivity arises through anti-syn isomer interconversion, enabled by an iterative retro-aldol/aldol reaction.Fil: Karak, Milandip. Universidade Federal de Viçosa; Brasil. Universidade Federal de Minas Gerais; BrasilFil: Barbosa, Luiz C. A.. Universidade Federal de Minas Gerais; Brasil. Universidade Federal de Viçosa; BrasilFil: Acosta, Jaime A. M.. Universidade Federal de Minas Gerais; BrasilFil: Sarotti, Ariel Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Química Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Química Rosario; ArgentinaFil: Boukouvalas, John. Laval University; Canad