Cyclohexanol and esters

Cyclohexanol and esters undiluted 15-25 9 Resistant little or no change in weight small effect on mechanical properties generally suitable for practical use Ertacetal C Quadrant EPP... 

Cyclohexanol and esters undiluted 100 9 Resistant little or no change in weight small Ketron PEEK GF-30 Quadrant effect on mechanical properties generally EPP Filler 30% Glass fiber suitable for practical use j 5 25 9 23 1 7 Good resistance Larpeek LATI Industria Termoplastici S.p.a. 23 9 No attack little or no absorption Victrex PEEK 23 9 " Victrex PEEK Victrex... 

Cyclohexanol and esters undiluted 15-25 2 Not resistant after a short time the material is seriously affected (considerable reduction of the mechanical strength and changes in weight) using the material under these conditions is not recommended PSU 1000 Quadrant EPP... 

Cyclohexanol and esters II 15-25 2 Partially resistant in course of time, there is a distinct deterioration in mechanical properties and a change in weight in many cases a short exposure may be considered allowable ... 

In the absence of ultrasound, the results show a substantial amount (49 %) of the dimer bicyclohexyl from the one-electron pathway, together with cyclohexylmethyl-ether, cyclohexanol and other products from the two-electron pathway (approx. 30%). The methyl cyclohexanoate ester (17%) can be thought to arise from the acid catalysed chemical esterification of the starting material with the solvent methanol. (As a result of the high current densities needed, (parasitic) discharge of the solvent methanol produces a large quantity of protons around the anode as a competitive reaction [54].)... 

The data in Table 2 show the potential of the Na2B407 based catalyst system tested over large number of representative alcohols. The primary alcohols were oxidized to the corresponding aldehydes at complete conversion of the alcohol and at 90-93% selectivity. The only by-products observed were the corresponding acid and minor amounts of the symmetrical ester (Entry 2, 3). Benzyl alcohol was quantitatively converted to benzaldehyde. The secondary alcohols, 4-methyl cyclohexanol and 4-methylpentanol were converted to the corresponding ketones at room temperature. 

By the same method ethyl a-cyclohexylacetoacetate (b.p. 146-148°/20 mm.) has been prepared in 34% yield from cyclohexanol and acetoacetic ester, and ethyl a-fer/.-butylaceto-acetate (b.p. 101-102°/20 mm.) in 10-14% yield from tert.-butyl alcohol and acetoacetic ester. 

If one allows betaine (73) to react with iV-benzoyl iV-phenylhydra-zine, one obtains iV.-N -dibenzanilidourea (76). The same compound is obtained by heating under reflux with water. A-Benzoyl-A-phenylhydrazinoformic ester (77) is formed using cyclohexanol and ethanol. 

DinitTKx k, J. R. and Turner, W. A., Synthesis and stereochemistry of 2-dimethylaminome-thyl-6-phenyl cyclohexanols and related esters with antimicrobial activity. Can. J. Phann. Sci., 9. 33, 1974. 

When the acetic acid solutions of cyclohexanol and dichromate were mixed at 25°C rather than at 15°C the yield of crude cyclohexanone was only 6.9 g. A clue to the evident importance of the initial temperature is suggested by an experiment in which the cyclohexanol was dissolved in 12.5 mL of benzene instead of 10 mL of acetic acid and the two solutions were mixed at 15°C. Within afew minutes orange-yellow crystals separated and soon filled the flask the substance probably is the chromate ester, (CsHnOfjCrOj. When the crystal magma was let stand at room temperature the crystals soon dissolved, exothermic oxidation proceeded, and cyclohexanone was formed in high yield. Perhaps a low initial temperature ensures complete conversion of the alcohol into the chromate ester before side reactions set in. 

The well-known oxidations of primary and secondary alcohols with Cr species proceed through chromate esters. The definitive mechanistic expeii-ments " demonstrating that previously observed chromate esters were indeed on the reaction pathway showed that either formation or decomposition of the ester could be rate-determining. The rates of oxidation of cyclohexanol and the secondary hydroxyl group of a very steiically hindered steroid in aqueous acetic acid were measured as a function of the solvent composition. The former increased radically as the acetic add concentration increased whereas the latter remained invariant. The former exhibited a primary deuterium kinetic isotope effect of 5, whereas there was no KIE on the oxidation of the crowded steroid. Therefore, the rate-determining step in the oxidation of the cyclohexanol was decomposition of the chromate ester and in the oxidation of the steroid it was its formation, with the ester an obligate intermediate in both reactions. 

Preparation. The ester is prepared from equimolar amounts of cyclohexanol and boric acid in refluxing toluene two molar equivalents of water are formed and separated. Yield 95%. Molecular weight studies show that metaborates exist as trimers ... 

Initially, cyclohexane is oxidized to the intermediate cyclohexyl hydroperoxide, CHHP. Then, the obtained CHHP is decomposed into the desired components cyclohexanone and cyclohexanol however, it is also partly decomposed into undesired by-products. A part of the formed cyclohexanol is further oxidized to cyclohexanone and a part of the formed cyclohexanone is converted to by-products. Part of the cyclohexane oxidation by-products are further destroyed (not shown in this figure). The by-products finally obtained include, in various amounts, acids such as adipic acid, e-hydroxycaproic acid, glutaric acid, succinic acid, valeric acid, caproic acid, propionic acid, acetic acid, formic acid, and noncondensable gases such as CO and CO2. In addition, several esters are formed between mainly cyclohexanol and the various carboxylic acids. The destinations of these by-products are quite diverse and depend on the producer for example, some of these byproducts are fed to combustion units for heat recovery purposes, while others are used as feedstock for chemicals such as 1,5-pentanediol, 1,6-hexanediol (HDO), and caprolactone. In general cyclohexanol is recovered from esters in a biphasic saponification step. 

Show how you would make the methanesulfonate ester of cyclohexanol, beginning with cyclohexanol and an appropriate acid chloride. 

Spiniello, M., White, J. M. (2003). Low-temperature X-ray structural studies of the ester and ether derivatives of cis- and trans-4-tert-butyl cyclohexanol and 2-adamantanol apphcation of the variable oxygen probe to determine the relative a -donor ability of C-H and C-C bonds. Organic, Biomolecular Chemistry, 1, 3094—3101. This paper also provides an excellent historic survey of this problem. 

Labeled benzene ring from 1,5-dlbromldes and labeled carboxylic acid esters via cyclohexanols and cyclohexenes... 

Steric effects were also noted in the oxidation of /9-substituted cyclopentanols by Cr. The rates show only a small increase relative to cyclohexanol and, since 1,3-non-bonded interactions in five-membered rings may be relieved by pseudorotation, steric acceleration by torsional strain is indicated. Similarities in the activation parameters suggest a common mechanistic path involving chromate esters. 

Figure 136. A values for the esters of the carboxylic acids shown with ran5-2-phenyl-l-cyclohexanol and 9-AHA. Data for 9-AHA given in boldface type.

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