ELIMINATION OF HYDROGEN FLUORIDE FROM FLUORINATED SUCCINIC ACIDS.(II) KINETICS OF DEHYDROFLUORINATION OF FLUORO-, 2,2-DIFLUORO-, MESO- AND DL-2,3-DIFLUORO-, AND TRIFLUOROSUCCINIC ACIDS

Article abstract of DOI:10.1016/S0022-1139(00)81275-0

Elimination of hydrogen fluoride from fluorosuccinic acid gave fumaric acid, from 2,2-difluorosuccinic acid, meso- and DL-2,3-difluorosuccinic acid fluorofumaric acid, and dehydrofluorination of trifluorosuccinic acid afforded difluoromaleic acid.Kinetic data based on 1H NMR measurements are presented for temperatures of 60 deg C, 75 deg C and 90 deg C.All the dehydrofluorinations follow second order kinetics.Activation energies for the dehydrofluorination of the above acids were found to be: 19.3, 17.3, 18.8, 17.9 and 18.3 kcal, respectively.Since both diastereomeric 2,3-difluorosuccinic acids give fluorofumaric acid as the only product of dehydrofluorination, one of them (DL) undergoes trans elimination while the other (meso) must undergo cis elimination.