Enantioselective Henry Addition of Methyl 4-Nitrobutyrate to Aldehydes. Chiral Building Blocks for 2-Pyrrolidinones and Other Derivatives

A catalytic highly enantioselective Henry addition of methyl 4-nitrobutyrate to aldehydes using a Cu(II) amino pyridine complex as catalyst is described. The products resulting from this reaction constitute a new, highly versatile family of chiral building blocks as a result of the presence of three different functional groups on the molecule. These products have been transformed into nonracemic chiral gamma-lactams, 5-hydroxy-5-substituted levulinic acid derivatives, and delta-lactones.