Enamine chemistry. Part 25. Preparation and carbon-13 nuclear magnetic resonance spectra of N-alkyl-morpholines and -pyrrolidines. Comparison with the carbon-13 spectra of the corresponding acyclic enamines

Abstract

The preparation and ¹³C chemical shifts of a series of N-alkyl-morpholines and -pyrrolidines are reported. The α-and β-effects of the amine moieties have been evaluated and compared with those operating in the corresponding enamines and with the α- and β-effects of an isopropyl group. The factors affecting the relative magnitude of these effects are discussed.