Nitroalkylation and nitroalkenylation reactions of γ-lactone enolates. A facile ring switch from polysubstituted γ-lactones to polysubstituted γ-lactams
作者:C. Forzato、P. Nitti、G. Pitacco、E. Valentin、S. Morganti、E. Rizzato、D. Spinelli、C. Dell'Erba、G. Petrillo、C. Tavani
DOI:10.1016/j.tet.2004.07.084
日期:2004.11
Michael addition of lithium enolates of gamma-butyrolactone 1 and alpha-methyl-gamma-butyrolactone 1' to (E)-1-nitropropene 2, (E)-beta-nitrostyrene 3 and (E)-2-vitro-1-phenylpropene 4 is described. Reactions of the lithium enolate of 1' with 2 and 4 occurred with high diasteroselectivity (80 and 92% d.e., respectively). Reactions of the zinc enolate of 1' with two beta-nitroenamines and two methylthiosubstituted 1-amino-2-vitro-1,3-dienes were also examined. Catalytic reduction of the nitroalkylated and nitroalkenylated products allowed the achievement of functionalized gamma-lactams and/or cyclic hydroxamic acids. (C) 2004 Elsevier Ltd. All rights reserved.