3190 ROBERT E. LUTZ AND WILLIAM P. BOYER VOI. 63 acid reagent proceeded with great facility and gave the cis-unsaturated diketone which, surprisingly, proved to be sufficiently stable to persist under the conditions of the experiment.-4 similar series of experiments in the phenylmesityl series was blocked by failure to obtain a crystalline cis-unsaturated diketone either from the trans-compound or from the furan. These experiments as far as ...