Unsaturated diaziridines thermal cleavage possibilities: Disrotatory or conrotatory?

Ab initio calculations are carried out at UB3LYP/6-311++G (3df, 2p) levels of theory, on electrocyclic thermal cleavage of four (R) derivatives of diaziridines, 1(X-R), to their corresponding (Z) and (E) azomethine imides (2(X-Z), 2(X-E), 3(X-Z) and 3(X-E)), where X = -H, -Me, -t-Bu and -Ph. Cleavage of 3(X-R) Series to 3(X-Z) (Path 3) emerged as the more favored, for producing the most stable products, 3(X-Z). In IRC calculations that were shown in Path 3 and 4, C-6-N-5 bond was cleavage, before reaching reaction rate determinating step (transition state).