... The Cyclization of 3-Isopropenyl-6-oxoheptanoic Acid JOSEPH WOLINSKY AND DAVID CHAN Department of Chemistry, Purdue University, Lafayette, Indiana Received December 17, 1965 ... (14) H. Pines and H. E. Eschinazi. J . Am. Chem. Soc., 77, 6314 (1955). ...