74960-16-0Relevant articles and documents
Heterocyclic Polyfluoro-compounds. Part 31. Photochemical Oxetan Formation from Fluoroketones and Perfluoroaldehydes and 1,2-Difluoroethylene
Barlow, Michael G.,Coles, Barrie,Haszeldine, Robert N.
, p. 2258 - 2267 (2007/10/02)
The photochemical addition of five fluoroketones (hexafluoro-, chloropentafluoro-, 1,3-dichlorotetrafluoro-, 1,1,3-trichlorotrifluoro-, and 1,1,1-trifluoro-propan-2-one) and the perfluoroaldehydes RFCHO (RF=CF3, C2F5, or n-C3F7) to (Z)- or (E)-1,2-difluoroethylene at λ > 300 nm has been studied.Oxetan formation dominates with hexafluoropropan-2-one, but there is increasing competition from reactions involving free radicals arising from photolysis of the ketone as the chlorine content is increased.Oxetan formation occurs with little stereospecificity.The aldehydes give r-2-perfluoroalkyl-t-3,c-4-, and -c-3,t-4-, and -t-3,t-4-difluoro-oxetans, in the ratio 1.0 : 1.7 +/- 0.2 : 1.3 +/- 0.1, respectively, and in high yield (78-94percent).A small amount of olefin isomerisation occurred. Flow pyrolysis of the oxetans from hexafluoroacetone yields (Z)- and (E)-1,2-difluoroethylene and the olefin (CF3)2C=CHF, the oxetan yields the olefins (Z)- and (E)-CHF=CHF and (CF2Cl)2C=CHF, and r-2-pentafluoroethyl- or heptafluoro-n-propyl-c-3,t-4-difluoro-oxetans yield mainly the olefins (Z)- and (E)-RFCHC=CHF (RF=C2F5 or n-C3F7).
