Competitive cyclopropanation, allylic insertion, and Wolff rearrangement have been observed in the catalytic decomposition of ethyl 3-diazo-2-oxopropionate in the presence of cyclohexene. The course of the decomposition could be controlled by use of transition-metal catalysts: highly selective formation of the norcaryl derivative 2 or the malonate 4 could be achieved by appropriate choice of catalyst. The formation of 4 has been interpreted by the ...
