Reaction with alcohols of 1-bromo(chloro)-1,2-epoxyheptafluorobutanes and 1,2-epoxyperfluorobutane.: Preparation of α-bromo-, α-chloro-, and α-alkoxyhexafluorobutyric acids esters

1-Bromo(chloro)-1,2-epoxyheptafluorobutanes reacted with primary and secondary alcohols by two concurrent routes giving a mixture of esters of alpha-alkoxy- and alpha-bromo(chloro)-hexafluorobutyric acids with growing content of the latter on increasing the bulk of the nucleophilic agent. 1,2-Epoxyperfluorobutane under the same conditions was converted into alpha-alkoxyhexafluorobutyric acid esters. Reaction of 1-bromo- 1,2-epoxyheptafluorobutane and 1,2-epoxyperfluorobutane with potassium tert-butylate in tert-butanol resulted in tert-butyl alpha-bromohexafluorobutyrate and heptafluorobutyrate respectively due to the forced attack of the bulky nucleophile on the terminal carbon atom of the epoxy ring.