The rhodium (I1) acetate catalyzed behavior of 0-[(propeny1oxy) methyll-a- diazoacetophenone was studied. The results obtained are consistent with a mechanism in which the key step involves intramolecular cyclization of the ketocarbenoid onto the oxygen atom of the side chain to give an oxonium ylide intermediate which undergoes either CH insertion or a competitive 2, 3-sigmatropic rearrangement. The reaction of l-diazo-9- ...
