Azastilbenes can undergo several photochemical reactions such as cis-trans isomerization, cyclodimerization into cyclobutane cornpounds (part 11), and intramolecular cyclizations with formation of dihydroazaphenanthrenes.'-12 It was the aim of the present work to synthesize severail symmetric and asymmetric azastilbenes and to examine the influence of their structure on their photochemical behavior. In the present paper the synthesis of these ...
