Treatment of Cl2CF2 with a base in the presence of an olefin gave chlorofluorocyclopropanes (I), which were distd. in a spinning band column and taken up in tetrahydrofuran (THF). This soln. was added dropwise to a stoichiometric amt. of Na in liquid NH3 and the fluorocyclopropane was isolated from the dried residue. A 65% yield of 1,1,2,2-tetramethyl-3-fluorocyclopropane was obtained in this manner together with a 45% yield of the corresponding chlorofluorocyclopropane. Li in 1:3 tert-BuOH-THF or Na in MeOH also reduced chlorofluorocyclopropanes, but halogen-free cyclopropanes were formed as by-products. [on SciFinder (R)]