Catalytic Enantioselective N-Nitroso Aldol Reaction of γ,δ-Unsaturated δ-Lactones
摘要:
A catalytic asymmetric N-nitroso aldol reaction of gamma,delta-didehydro-delta-lactones with nitrosoarenes was achieved using chiral tin dibromide as the chiral precatalyst and sodium ethoxide as the base precatalyst in the presence of ethanol. Optically active alpha-hydroxyamino ketones with up to 99% ee were regioselectively obtained in moderate to high yields from various delta-aryl-substituted gamma,delta-didehydro-delta-valerolactones and o-substituted nitrosoarenes.