CC1= CC1CF2CF2CF2. The 2-butene, which we prepared previously, 2 can now be claimed as the cis-isomer by comparing our data with those just published by Brice and his co-~ orkers.~ The cyclopentene is new; in one of its attempted synthe-ses, a new perfluoroalkyne CF~ C= C-CFZCF~ was obtained instead of the cyclic compound. When Newby2 first reported his synthesis of CF3CF= CFCF3 by dechlorination of ...
