The reaction of anhydrous, neutral alumina, activity grade I, with a 1, l-difluorocycloalkane produces the corresponding 1-fluorocycloalkene in 20-707, yield. In this way, 1- fluorocyclopentene, 1-fluorocyclohexene, 1-fluorocydoheptene, 1-fluorocyclooctene, 1- fluorocyclododecene, and 4-methoxy-1-fluorocyclohexene were prepared and characterized, principally by proton and fluorine nmr and infrared spectra. The starting ...