Collect. Czech. Chem. Commun. 1980, 45, 415-422

Ionic dimerisation of methyl trifluoropropenoate

Oldřich Paleta, Václav Havlů and Václav Dědek

Department of Organic Chemistry, Institute of Chemical Technology, 166 28 Prague 6


Dimerisation of methyl trifluoropropenoate (I) in solvents in the presence of potassium fluoride affords stereoisomeric dimethyl perfluoro-(4-methyl-2-pentene)dioates (III), the ratio of which depends on the reaction conditions. The reaction is accompanied by formation of methyl 2,3,3,3-tetrafluoropropenoate (IV), arising by proton transfer from the solvent to the carbanionic intermediate. Under suitable conditions complete conversion of the propenoate can be achieved and the dimer is obtained in 80-90% yield. Principal steps of the dimerisation were proved and the formation of configurational isomers is discussed in terms of kinetically controlled reaction.