Conformational states of methylamides of N-acetyl α-amino acids and their N-methyl derivatives I. Infrared spectra

1. The IR spectra of methylamides of N-acetyl α-amino acids and their N-methyl derivatives in CCl4 and CHCl3 solutions have been investigated. An assignment of the bands of the NH and CO stretching vibrations in the folded (with an intramolecular H bond) and the extended conformations has been made.