Results 2, ZDifluoro-1-vinylcyclopropane, 1, was prepared via Burton's unambiguously by its spectral properties, most notably its 'H and I9F NMR spectra (see Experimental Section). The thermal isomerization of 3 was carried out, in the gas phase, in a wellconditioned Pyrex vessel with the results shown below. Yields were determined by direct analysis of the gaseous product mixture by GLPC using an internal standard, while the efficacy of this ...