Elimination reactions of 1,2-dihalo-2,3,3-trifluorocyclobutanes

Elimination reactions on isomeric mixtures of $\text{cis}$ and $\text{trans}$ 1,2-dihalo-2,3,3-trifluorocyclobutanes are reported. In zinc-promoted dehalogenations a steady decrease in the relative amount of the $\text{trans}$ isomers compared to the $\text{cis}$ isomers occured, with 2,3,3-trifluorocyclobutene as the sole product. The $\text{cis}$ isomers reacted at a faster rate in potassium hydroxide induced eliminations to yield a slight predominance of 1-halo-2,3,3-trifluorocyclobutenes over 3-halo-3,4,4-trifluorocyclobutenes. However, with triethylamine as the inducing base, an increased rate of elimination from the $\text{trans}$ isomers was noted along with almost exclusive formation of 3-halo-3,4,4-trifluorocyclobutenes.