POLYFLUORO-1,2-EPOXY-ALKANES AND POLYFLUORO-1,2-EPOXY-CYCLOALKANES .6. THE SYNTHESIS AND SOME REACTIONS OF 1-TRIFLUOROMETHYLNONAFLUORO-1,2-EPOXYCYCLOHEXANE

Aqueous sodium hypochlorite in acetonitrile gave, respectively, 1-trifluoromethylnonafluoro-1,2-epoxycyclohexane (2) from 1-trifluoromethylnonafluorocyclohex-1-ene, and the bis-(1, 2):(4, 5)-epoxide from 1-trifluoromethylheptafluorocyclohexa-1,4-diene. From epoxide (2) and lithium aluminium hydride, 1H2H-2-trifluoromethyloctafluorocyclohexanol was formed, and (2) with potassium fluoride afforded potassium 2-trifluoromethyldecafluorocyclohexanolate (6). The two stereoisomers of 1-methoxy-2-trifluoromethyldecafluorocyclohexane were obtained from alkoxide (6) and dimethyl sulphate: warming of (6) gave 2-trifluoromethylnonafluorocyclohexanone (9). Epoxide (2) with sodium methoxide afforded two acyclic products, methyl decafluoro-6-methoxyhept-5-enoate (10) and methyl nonafluoro-5, 6-dimethoxyhept-5-enoats, via a sequence which included a ring-opening haloform cleavage stage. Reaction of ketone (9) with sodium methoxide also gave two acyclic esters, (10) and its positional isomer, methyl decafluoro-6-methoxyhept-4-enoate, as an inseparable mixture. Again, ring-opening was by a heloform cleavage. © 1990.