EFFECT OF REMOTE HETEROATOM SUBSTITUENTS ON STEREOCHEMISTRY IN 1,2 H MIGRATION TO DIVALENT CARBON. EVIDENCE FOR " NEGATIVE " HYPERCONJUGATION OF CARBENE LONE PAIR
Aryloxymethylchlorocarbene generated by photolysis of the corresponding diazirine afforded α-aryloxy-β-chloroalkene.The thermodynamically less stable Z-products are the major isomers and its content becomes dominant as more electron-withdrawing groups are