Synthesis of 3-Carbomethoxy-3-methylcyclo-pentanone

Ruzicka has reported the preparation of 3-carbethoxy-3-methylcyclopentanone (I) through severa1 steps from ethyl levulinate. In the present investigation, a shorter synthesis of the corresponding methyl ester (II) was achieved from the adduct of butadiene with methyl methacrylate by the following route