Structural investigation of (Z)-N-acetyl-β(3′-pyridyl)-dehydroalanine methyl ester

The crystal and molecular structure of the methyl ester of (Z)-N-acetyl-beta(3prime-pyridyl)-dehydroalanine [methylZ-2-acetamido-3(3prime-pyridyl) propenoate] have been determined from three-dimensional X-ray data. Crystals are monoclinic, space groupP21]. The molecular [phgr=–51.5(5),psgr=157.0(4)°] conformation is discussed making reference to previous experimental results of analogous amino acid derivatives (in particular, ethyl (Z)-N-acetyldehydrophenylalaninate) and theoretical predictions. On the basis of He(I) and He(II) photoelectron spectra, a similar conformation is proposed for the title molecule in the vapor phase also.