38126-93-1Relevant articles and documents
POLYFLUORO-COMPOUNDS BASED ON THE CYCLOHEPTANE RING SYSTEM. PART 3. BICYCLIC COMPOUNDS MADE FROM DECAFLUOROCYCLOHEPTA-1,3-DIENE
Khalil, Abd E. M. M.,Stephens, Robert,Tatlow, John Colin
, p. 43 - 50 (1983)
Decafluorocyclohepta-1,4- and -1,3-diene and decafluorobicyclo(3,2,0)hept-6-ene were interconverted at ca 460 deg C, over packings such as sodium fluoride pellets or iron gauze.The 1,3-diene was converted by uv irradiation to the bicyclohept-6-ene, wich underwent oxidation to octafluorocycloheptane-1,2-dicarboxylic acid, and saturation by cobalt(III) fluoride to the bicycloheptane, whilst nucleophilic addition-elimination gave the 6H- and 6H,7H-bicyclo-6-enes (from NaBH4), and the 6-methoxy-6-ene (from MeOH/KOH).Decafluorocyclohepta-1,3-diene in a Diels-Alder reaction with ethylene afforded 6H,6H,7H,7H-decafluorobicyclo(3,2,2)non-8-ene.This adduct was oxidised to 1,2,2,3,3,4,4,5-octafluorocycloheptane-1,5-dicarboxylic acid, whilst cobalt(III) fluoride at 180 deg C fluorinated it to a mixture of 6H,6H-tetradeca- and 6H-pentadecafluorobicyclo(3,2,2)nonane.The latter with aqueous potassium hydroxide afforded tetradecafluorobicyclo(3,2,2)non-6-ene.
POLYFLUORO-COMPOUNDS BASED ON THE CYCLOHEPTANE RING SYSTEM. PART 5. OCTAFLUOROCYCLOHEPTA-1,3,5-TRIENE AND HEXAFLUOROTROPONE
Dodsworth, D. J.,Jenkins, C. M.,Stephens, R.,Tatlow, J. C.
, p. 41 - 60 (2007/10/02)
Decafluorocyclohepta-1,3-diene underwent reductive addition-elimination with sodium borohydride to give mainly 1H-nonafluorocyclohepta-1,3-diene, together with minor products, the 1H,4H-octafluoro-analogue and, most significantly, 5H-nonafluorocyclohepta-1,3-diene.Decafluorocyclohepta-1,4-diene, together with some 6H-nonafluorocyclohepta-1,4-diene and a trace of the 5H-1,3-diene.These last two dienes were important products, having hydrogen on allylic carbons.They could be dehydrofluorinated, either by bubbling through molten potassium hydroxide or, better, with powdered alkali in an inert medium.Unless special precautions were taken, such reactions yielded hexafluorotropone.With care however the primary product, octafluorocyclohepta-1,3,5-triene, could be isolated, but it was hydrolysewd rapidly, even by water, to give the tropone.Isomerizations and pyrolytic dehydrofluorinations of the major reduction products were carried out, but none yielded the triene or the tropone.It seemed that the triene was probably formed but decomposed to give perfluoroarenes.An interesting defluorination pathway was also operating, to give pentafluorobenzene. 2H-Nonafluorocyclohepta-1,3-diene was an isomerization product.Hexafluorotropone reacted with sodium methoxide in methanol to give 3,6-dimethoxytetrafluorotropone.
POLYFLUORO-COMPOUNDS BASED ON THE CYCLOHEPTANE RING SYSTEM. PART 2. THE 1H,3H- and 1H,4H-DODECAFLUOROCYCLOHEPTANES, DERIVED UNDECAFLUOROCYCLOHEPTENES AND DECAFLUOROCYCLOHEPTA-1,4- and 1,3-DIENE
Khalil, Abd E. M. M.,Stephens, Robert,Tatlow, John Colin
, p. 31 - 42 (2007/10/02)
From the mixture obtained by reaction of cycloheptane with cobalt(III) fluoride at 180-190 deg C, the cis- and trans-1H,3H- and 1H,4H-dodecafluorocycloheptanes were isolated.Each 1H,3H-compound was dehydrofluorinated by aqueous potash to 3H- and 4H-undecafluorocyclohept-1-ene, and thence decafluorocyclohepta-1,4- and 1,3-diene.The 1H,4H-isomers each gave 4H- and 5H-undecafluorocyclohept-1-ene and thence the two dienes on dehydrofluorination.The dichloro-adduct of the 5H-ene was reduced by lithium aluminium hydride, and the three possible 1H,2H,5H-undecafluorocycloheptanes were isolated.Likewise, the 4H-ene gave the 4 possible 1H,2H,4H-undecafluorides.All were identified by further fluorination with cobalt(III) fluoride at 160 deg C, to appropriate dodecafluorocycloheptanes.
