Sequential radical perfluoroalkylation - Nucleophilic cyclization. Synthesis of 2-perfluoroalkylidenemethyl and 2-perfluoroalkylmethyl-1,4-dioxanes from 1-O-allyl-1,2-diols

Article abstract of DOI:10.1016/0040-4020(96)00243-8

The title compounds were synthesized by radical addition of perfluoroalkyl iodide to 1-O-allyl-1,2-diols and subsequent nucleophilic cyclization according to one of the following procedures. Basic treatment of the iodo F-alkyl adduct gave an olefinic compound which is stereoselectively cyclized with an excess of base into the corresponding 2-perfluoroalkylidenemethyl-1,4-dioxane through as S(N)' process. The direct cyclization of the adduct into 2-perfluoroalkylmethyl-1,4-dioxane was achieved by a new and simple method using molecular iodine or positive halogen reagents (DBH, NBS) for the activation of the carbon-iodine bond.