Abstract: Several o-carboalkoxy-a-diazoacetophenone derivatives were prepared, and their rhodium (I1) acetate catalyzed behavior was studied. The results are consistent with a mechanism in which the key step involves intramolecular cyclization of the keto carbenoid onto the oxygen atom of the ester carbonyl to give a resonance-stabilized six-membered carbonyl ylide intermediate. The ylide dipole is then trapped internally by the neighboring ...
