(Z)- and (E)-5-Arylmethylenehydantoins: spectroscopic properties and configuration assignment

Abstract

Both (Z)- and (E)-5-arylmethylene-1-methylhydantoins have been obtained directly in substantial proportions from condensations of 1-methylhydantoin with aromatic aldehydes. However, the products of similar condensations of hydantoin or 3-methylhydantoins consist almost entirely of the Z-isomers. The configurations of all the 5-arylmethylenehydantoins prepared can be unambiguously assigned by consideration of their ¹H and ¹³C n.m.r., i.r., and u.v. spectra. The mass spectra of the isomers show similar fragmentation patterns.