Cyclohexyl ether

See cyclohexyl ether in this section M. Engelhard and R. B. Merrifield, J. Am. Chem. 

In a variation of the scheme above, alkylation of p-hydroxy-benzoic acid with cyclohexyl iodide affords the cyclohexyl ether, 55. (Under alkaline reaction conditions, the ester formed concurrently does not survive the reaction.) Acylation of the acid chloride obtained from 55 with the preformed side chain (56) gives cyclomethycaine (57). ... 

Write the mechanism of the acid-catalyzed cleavage of tert-butyl cyclohexyl ether to yield cyclohexanol and 2-methylpropene. 

Production of considerable amounts of cyclohexanol and cyclohexanone as well as benzaldehyde and benzoic acid in the oxidation of benzyl cyclohexyl ether shows the primary radical to be CgHjCHOCeHjj. Abstraction from aliphatic C-H bonds cannot occur in the case of diphenyl ether which is oxidised rapidly, and removal of a 7t-electron is likely. 

We have shown that a number of aliphatic ethers, containing steric-ally accessible p-hydrogen atoms, are cleaved in good yield when the tetrahalogenoanthranilic acids are diazotised in ethers 128,59). Diethyl ether is cleaved to the tetrahalogenophenetole (90) and methyl-cyclohexyl ether affords the tetrahalogenoanisole. In this latter reaction we were able to detect cyclohexene and therefore a plausible, but as yet unproved, mechanism is as shown. 

Equivalent amounts of aldehydes and alkoxytrimethylsilanes react to form unsymmetrical ethers in near quantitative yields in the presence of either trimethylsilane or triethylsilane and catalytic amounts (ca. 10 mol%) of TMSI in dichloromethane.329,333,334,341 The procedure is particularly convenient experimentally when trimethylsilane is used with TMSI because the catalyst provides its own color indicator for the reduction step (color change from deep violet to vivid red-gold) and the only silicon-containing product following aqueous workup is the volatile hexamethyldisiloxane (bp 99-100°). It is possible to introduce trimethylsilane (bp 7°) either as a previously prepared solution in dichloromethane or by bubbling it directly into the reaction mixture. Cyclohexyloxytrimethylsilane and n-butanal react by this method to give a 93% isolated yield of n-butyl cyclohexyl ether (Eq. 183).334... 

Complex hydrides were used for reductions of organometallic compounds with good results. Trimethyllead chloride was reduced with lithium aluminum hydride in dimethyl ether at —78° to trimethylplumbane in 95% yield [1174, and 2-methoxycyclohexylmercury chloride with sodium borohydride in 0.5 n sodium hydroxide to methyl cyclohexyl ether in 86% yield [1175]. 

Iodocyclohexane has been prepared by the action of phosphorus and iodine on cyclohexanol,2 and from hydrogen iodide and cyclo-hexanol,3 chlorocyclohexane,4 or cyclohexyl ether.5 It has also been prepared by reaction of potassium iodide and chlorocyclohexane.6... 

In order to study the hydrogenolysis in phenyl ether and its relationship to the formation of intermediates, Fukuchi and Nishimura hydrogenated phenyl ether and related compounds over unsupported ruthenium, rhodium, osmium, iridium, and platinum metals in f-butyl alcohol at 50°C and the atmospheric hydrogen pressure.151 The results are shown in Tables 11.11 and 11.12. In general, the greater part of the initial products as determined by an extrapolation method has been found to be cyclohexyl phenyl ether, phenol, and cyclohexane (Table 11.11). Over ruthenium, however, cyclohexanol was found in a greater amount than phenol even in the initial products. Small amounts of cyclohexyl ether, 1-cyclohexenyl cyclohexyl ether, cyclohexanol, cyclohexanone, and benzene were also formed simultaneously. 

Various noncarbohydrate replacements for this disaccharide unit have been investigated. These include ortho- and para-benzenedimethanol (— 71 and 72) [148], a lactam diol (- 73) [146], several flexible linkers (- 74-76) [149-151] and aryl-cyclohexyl ethers (— 77 and 78) [152,153]. In all cases, the application of noncarbohydrate building blocks led to inactive derivatives (Figure 16.27), presumably because of entropy costs associated with the conformational flexibility of these spacers and the absence of pharmacophoric groups that are equivalent to those found on the galactose moiety. 

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