Etude De La Conformation D'oximes Thiopheniques

The condensation of 2,5-diformylthiophene with hydroxylamine hydrochloride leads to the formation of three isomers. Two isomers 1′ and 1” present a second order axis of symmetry; compound 1′ is present with the configuration ZZ and exists in the conformation a and compound 1” is present with the configuration EE and exists in the conformation b. The last isomer 1”′ presents the e (Z,E) conformation.