Cyclohexyl ester

Methyl, ethyl, n-propyl, isopropyl, n-hutyl, benzyl, cyclohexyl esters of formic, acetic, oxalic, succinic, tartaric, citric, benzoic, salicylic (and other substituted benzoic acids), phthalic and cinnamic acids phenyl esters of acetic, benzoic and salicylic acids. 

Cleavage is effected with acid. The following table compares the acidolysis rates with Bn and cyclohexyl esters in TFA/phenol at 43°. The Dmp group reduces aspartimide formation during Fmoc-based peptide synthesis. 

Cyclopentyl Ester RCO2-C-C5H9 Cyclohexyl Ester RCO2-C-C6H11... 

Benzenesulfomc aad, 4-methyl-, cyclohexyl ester [Cyclohexanol, p-toluenesul-fonate], 55, 112... 

Bistline and Stirton compared the CMC values of ester sulfonates with cyclic ester groups [54]. The phenyl esters have higher values than benzyl and cyclohexyl esters. The influence of the structure of the ester group decreases with increasing chain length of the hydrophobic fatty acid group. The cyclic esters of a-sulfostearic acid, for example, have nearly the same CMC values. 

JP Tam, TW Wong, MW Reimen, FS Tjoeng, RB Merrifield. Cyclohexyl ester as a new protecting group for aspartyl peptides to minimize aspartimide formation in acidic and basic treatments. Tetrahedron Lett 4033, 1979. 

Acetic acid, chloro-, 5-methyl-2-(l-methyl-l-phenylethyl)cyclohexyl ester, [lR-(la,28,5a)]-, 65, 203... 

Methyl-2-(l-methyl-1-phenylethyl)cyclohexanone, (2S.5R)- Cyclohexanone, 5-methyl-2-(l-methyl-l-phenylethyl-, (2S-cis)- (65337-06-6), 65, 203 5-Methyl-2-(l-methyl-l-phenylethyl)cyclohexyl chloroacetate, (1R,2S,5R)- Acetic acid, chloro-, 5-methyl-2-(1-methyl-1-phenylethyl)cyclohexyl ester, [lR-(la,Z0,5a)]- (71804-27-8), 65, 203 5-Methyl-2-[l-methyl-l-(phenylmethylthio)ethyl]cyclohexanone, cis- and trans 65, 215... 

Fig. 10. (W,)2 parameter used in Eq. 51. The figure depicts the OR2 moiety of the cyclohexyl esters of L-asparthyl-aminoacetic acid (31)611 (reproduced with permission from the American Chemical Society)...

R,2S,5R)-(-)-Menthyl (S)-p-toluenesulfinate Menthol, (-)-, (S)-p-toluenesulfinate (8) Benzenesulfinic acid, 4-methyl-, 5-methyl-2-(1-methylethyl)cyclohexyl ester,... 

Oxidation catalyzed with boric acid (160-175°C, 8-10 atm) results in the formation of cyclohexyl esters.878,879 After hydrolysis a product mixture containing mainly cyclohexanol is formed.878 Since borate esters are less sensitive to further oxidation, better yields are usually achieved (85% at 12% conversion).872... 

Sipalin AOM. Ger trade name for the methyl-cyclohexyl ester of adipic acid. It was incorporated in solvents for NC (such as 75/25 butyl acetate/ethyl ale), the soln being used to coat electric detonator fuseheads by a dipping procedure. The Sipalin resulted in a NC varnish coating which was less permeable to moisture and less readily cracked... 

TABLE 9. Ratio of diequatorial (46a) and diaxial (46b) conformers of 2-trimethysilyl cyclohexyl esters... 

Analysis of the crystal structure of the p-nitrobenzoate and 2,4-dinitrobenzoate derivatives of ewrfo-3-(trimethylsilyl)-ewrfo-2-norborneol 47, in which the Si—C and C—O bonds are in the synperiplanar geometry, showed that there was no significant lengthening of the C—O bond in these cases64. By comparison, the cyclohexyl ester 48, in which the Si—C and C—O bonds are in the antiperiplanar conformation, did show a significant lengthening of the C—O bond compared to model compounds64. 

The known alkaloid heptaphylline has been isolated from the roots of Clausena harmandiana Pierre (Rutaceae) along with two new carbazole alkaloids identified as 2-hydroxy-3-formyl-7-methoxycarbazole (58) and 7-methoxyheptaphylline (59). The H- and l3C-NMR spectra have been analyzed and used to position the various functional groups (54,55). Other carbazole alkaloids isolated from the roots of Murraya siamensis Craib are identified as murrayanine, girinimbine, and mukonal, which occur together with heptaphylline and compounds 58 and 59 (56-55). Three new alkaloids have also been isolated from M. siamensis and named 3-formyl-2,7-dimethoxycarbazole (60), 3-formyl-2-methoxylcarbazole (O-methylmukonal) (61), and 7-methoxymurrayacine (62) (59). From the roots of Rauwolfia serpentina, the new alkaloid indobine (63) (60), the benzyl ester, and indobinine (64) (61), the cyclohexyl ester of indolepropionic acid, have been isolated and identified. 

Figure 2. Left Preparative-scale enantiomeric separation of N-TFA-alanine tert,-butyl ester on N-TFA-(L)-valine-(L)-valine cyclohexyl ester (experimental conditions cf, text). Right ORD spectra of the two isolated fractions corresponding to the marked areas (Gil-Av and Feibush, 1967).

The strongest response (largest slope) of the C-OR bond distance to the electron demand of the OR substituent occurs for 117, which has an oxygen lone pair anri-periplanar to the C-OR bond. The cyclohexyl esters 116 in which the C-C bond is anri-periplanar to the C-OR bond show a much weaker response of the C-OR distance to the electron demand of the OR substituent. Thus the slopes of the lines [r(C-OR) vs. pA- (ROH)] appear to provide qualitative measures of the donor abilities of orbitals that are anri-periplanar to the C-OR bond. 

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