Crystal structure analysis of N‐acetylated proline and ring size analogs

Abstract

Crystal structures of N‐acetylated proline and homologs with four‐ and six‐membered rings (azetidine carboxylic acid and piperidine carboxylic acid) were obtained and compared. The distinctly different conformations of the four‐, five‐, and six‐membered rings reflect Bayer strain, n → π* interaction, and allylic strain, and result in crystal lattices with a zigzag structure.