Synthesis and polymerization of fluorinated monomers bearing a reactive lateral group.: Part 6 -: synthesis of trifluorovinyl epoxide and its 1,2-diol

The preparation of the new omega-epoxide and 1,2-dihydroxy trifluorovinyl monomers useful as comonomers in the copolymerization of commercially available alkenes is presented. The addition of 1-iodo-1,2-dichloro-1,2,2-trifluoroethane to allyl acetate led quantitatively to the expected chlorotrifluorinated-2-iodo-1-acetate which underwent a thermal rearrangement yielding RFClCH2CH(OAc)CH2I even in the presence of a radical initiator that started to decompose at mild temperature. Whatever the amount of rearranged product, both these iodoacetates formed epoxides in alkali media giving two new compounds GRAPHICS and GRAPHICS in high yields. Dechlorination yielded the trifluorovinyl epoxide GRAPHICS (in 40% yield) and side products from the ring opening of the oxirane group. The mixture of halogenated epoxides was quantitatively hydrolysed into the halogenated -1,2-diol which was dechlorinated into F2C=CFCH2CH(OH)CH2OH in 58% yield. All these products and intermediates were characterized by H-1,F-19 and C-13 NMR spectroscopy. (C) 1999 Elsevier Science S.A. All rights reserved.