The synthesis of 1-vinyl-1, 2, 2, 3, 3-pentafluorocyclopropane (1) and the kinetics of its thermal, unimolecular rearrangement to 1, 4, 4, 5, 5-pentafluorocyclopentene (2) are reported. Kinetic data were obtained by gas-phase 19F NMR at 80–120° C, and the activation parameters for the rearrangement of 1 to 2 are: Δ G‡(100° C)= 28.7 kcal/mol, Δ H‡= 26.7 kcal/mol, and Δ S‡=− 5.5 eu (logA= 12.7, Ea= 28.4 kcal/mol). Vinyl ( ...
