The synthesis of 1-trifluoromethylcyclopropane, 1-methyl-1-trifluoromethylcyclopropane, l- trifluoromethyl-1, 2, 2-trifluorocyclopropane and ethyl (2-methyl-2-trifluoromethyl)- cyclopropanecarboxylate has been achieved by the addition of diazo compounds to fluorinated olefins. The cyclic structure of the products has been confirmed by infrared analysis. This method appears to have general application. The Freund reaction resulted ...
[Dolbier, William R.; Sellers, Simon F.; Al-Sader, Basil H.; Fielder, Thomas H. Journal of the American Chemical Society, 1981 , vol. 103, # 3 p. 717 - 718]