Fluorinated epoxides: 6. Chemoselectivity in the preparation of 2-[(heptafluoroisopropyl)methyl]oxirane from iodoacetate and iodohydrin precursors

Fluorinated iodoacetate (CF3)2CFCH2CHICH2OAc (1) (prepared by radical addition of perfluoroisopropyl iodide to allyl acetate) and fluorinated iodohydrin (CF3)2CFCH2CHICH2OH (2) (prepared from 1) were converted to the corresponding perfluoroalkylated oxirane (CF3)2CFCH2CH(O)CH2 (3) in the yield of 62%. The chemoselectivity of the oxirane formation appeared to be strongly dependent on the starting compound 1 or 2 and solvent used. Byproducts (CF3)2CFCHCHCH2OH (4) and (CF3)2CFCHCHCH2OAc (5) can form a major part of the products in the formation of epoxide 3.