(E, dipole alignment)(2, repulsion) and oppoeite to the configuration observed for azines, hydrazones, and semicarbazones of aldehydes and ketopes, where the more bulky group occupies the anti position. With R2= CH3 or CH2CH3, R1 groups smaller than tert-butyl do not force the hydrazonates into the Z configuration and even in the case R'= tert-butyl (R2= CH3), the E isomer predominates in the two-component system (2) at equilibrium. ...
