Ab initio studies of molecules with N---C---C=O units. Part 2. 1-Amino-2-propanone, 2-methylaminoethanal and 2-aminopropanal

A complete conformational analysis of all the monomethylated derivatives of 2-aminoethanal (2AE) was carried out using MO ab initio with the 6-31G^** basis set, and it was inferred that methylation produces an increase in stability with respect to the initial compound 2AE. Geometric tendencies related to the existence of intramolecular hydrogen bonding and anomeric effects are discussed. Finally, the differences between the ab initio results and those produced by the current consistent MM3(92) force field are analysed.