Study of 1,6-bis-O-(N-propionyl-L-alanyl)-1,6-hexanediol as a model compound of poly(ester amide)s derived from L-alanine

Abstract

The conformation of 1,6-bis-O-(N-propionyl-L-alanyl)-1,6-hexanediol (PrAHAPr) has been investigated in the crystalline state by X-ray analysis. PrAHAPr crystallizes in the monoclinic system, space group P21 with a = 4.861(4), b = 26.24 (1), c = 8.716 (3) A and β = 105.25 (1)°. In the crystal, the molecules are hydrogen bonded in a single direction that runs parallel to the a crystallographic axis. In spite of its chemical symmetry the molecule adopts an asymmetric conformation, where one of the alanine residues takes a folded conformation. PrAHAPr belongs to a series of model compounds for poly(ester amide)s derived from amino acids that we are presently investigating.