Stereoselective Synthesis of Substituted 5,6-Dihydro-2(1H)-pyridinones in Polyphosphate Media
Charles M. Marson, Ursula Grabowska and Asad Fallah, J. Org. Chem. 1994, 59, 291-296
δ-Lactams have been synthesized with excellent stereocontrol of substituents by condensing 3-alkenamides with aryl aldehydes in polyphoshpohoric ester. The scope of the condensation of 3-alkenamides with aryl aldehydes in several phosphate media is examined, and a rationale is proposed regarding γ-lactam versus δ-lactam formation.