Cyclohexyl fluorides

The chemical shift differences observed for these 1-fluoro-l-methyl-f-butylcyclohexanes, the cis- and rrans-9-nuomdecalins, and for 1-fluoroadamantane provide insight regarding the significant influence of conformation upon fluorine chemical shifts in fluorocyclohexanes. The relative chemical shifts of these various cyclohexyl fluorides can be rationalized simply on the basis of what is commonly known as an anomeric effect. That is, a vicinal hydrogen that is rigidly anti to a fluorine substituent will exhibit an anomeric double-bond/no-bond... 

When hydrogen fluoride adds to an olefin, the fluorine becomes attached to the carbon with the least hydrogen. Ethylene yields ethyl fluoride propylene yields isopropyl fluorine cyclohexene gives cyclohexyl fluoride. Cyclopropane yields n-propyl fluoride when the reaction is conducted very slowly at 0°, but if the temperature is not well regulated an isomerization takes place to yield isopropyl fluoride. The reactions are all non-catalytic and take place in paraffin or metal containers equally well. The yields are from 60 to 80%.46... 

Cyclohexyl Fluoride.48 In a copper container fitted with inlet, outlet and stirrer is placed 200 g. of anhydrous hydrogen fluoride. After cooling to —35°, 400 g. of precooled cyclohexene is added dropwise over a period of seventy-five minutes. The reaction mixture is poured into a copper beaker filled with cracked ice, stirred, decanted, dried, and distilled under 300 mm. pressure (b.p. 71-71.4°). The yield is 60% at 10° it is only 54%. 

Cyclohexylcyclohexanone, 180-181 Cyclohexyl fluoride, 627 N-Cyclohexylformamide, 382, 857, 878 Cyclohexylformyl peroxide, 57 Cyclohexylidenecyclohexylamine, 788 C clohexyl iodide, 94, 553, 873 C clohexyl isocyanide, 382, 857, 878 Cyclohexyl isothiocyanate, 181 Cyclohexylmagnesium bromide, 1232 Cyclohexyl methyl ether, 72-73 l-Cyclohexyl-3-(2-morpholinoethyl)-... 

In the case of a still less reactive halide, or one with a tendency to undergo dehydrohalogenation, it is advantageous to add a reactive halide such as 1-bromo-naphthalene or n-butyl bromide for entrainment. Thus the reaction of 0.05 mole of eyclohexyl chloride and 0.05 mole of 1-bromonaphthalene with 0.33 g. atom of magnesium and isopropanol (0.3 mole) in 50 + 20 ml. of decalin afforded a mixture of 83% of cyclohexane and 10% of cyclohexene (removable with sulfuric acid). By this procedure cyclohexyl fluoride gives cyclohexane (33%) and benzotrifluoride gives toluene (10%). Fluorobenzene is inert. 

Cyclohexyl fluoride has been carefully studied by Bovey et al. (1964a). The F19 magnetic resonance, although very complicated by the low symmetry of the coupled protons, exhibits a very large conformational... 

Table 16. Comparison between V(C,F) couplings and the occupation number of both antibonds belonging to the coupling pathway in the eq- and ax-epimers of cyclohexyl fluoride ...

Coumarin-3-carboxylic acid 8457 Cyclohexyl fluoride 5380 Dehydroacetic acid 82... 

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