Cyclohexane carboxylate derivatives

Other phenol derivatives that are used to form the backbone of an epoxy resin include bisphenol E, bisphenol F, resorcinol, brominated bisphenols, and more highly functionalized molecules such as tetrakisphenylolethane. Alcohols, amines, and carboxylic acids may be combined with epichlorohydrin to give a range of diglycidyl ether based epoxy resins. Non-aromatic, commercially available epoxides are produced by peracid epoxidation of alkenes and dienes, such as vinyl cyclohexene and esters of cyclohexane carboxylic acids [23]. The chemical formulas for two common uncured polymers are shown below ... 

Enolates derived from cyclic compounds such as cyclohexane carboxylic acid or cyclohexane carboxalde-hyde generate enolates that are unique. These enolates have an exocyclic double bond that can exist as ( ) and (Z) isomers. The facial and orientational bias in alkylation and condensation reactions of such enolates is influenced by the conformation of the ring it is attached to. Alkylidene cyclohexane enolates show a preference for equatorial attack, just as cyclohexanone derivatives do (sec. 4.7.C,D). 

The name naphthenic acid is derived from the early discovery of monobasic carboxyUc acids in petroleum, with these acids being based on a saturated single-ring stmcture. The low molecular weight naphthenic acids contain alkylated cyclopentane carboxyUc acids, with smaller amounts of cyclohexane derivatives occurring. The carboxyl group is usually attached to a side chain rather than direcdy attached to the cycloalkane. The simplest naphthenic acid is cyclopentane acetic acid [1123-00-8] (1, n = 1). 

The stmcture of vitamin A [11103-57-4] and some of the important derivatives are shown in Figure 1. The parent stmcture is aH-Zra/ j -retinol [68-26-8] and its lUPAC name is (all-E)-3,7-dimethyl-9-(2,6,6-trimethyl-l-cyclohexen-l-yl)-2,4,6,8-nonatetraen-l-ol (1). The numbering system for vitamin A derivatives parallels the system used for the carotenoids. In older Hterature, vitamin A compounds are named as derivatives of trimethyl cyclohexene and the side chain is named as a substituent. For retinoic acid derivatives, the carboxyl group is denoted as C-1 and the trimethyl cyclohexane ring as a substituent on C-9. The stmctures of vitamin A and -carotene were elucidated by Karrer in 1930 and several derivatives of the vitamin were prepared by this group (5,6). In 1935, Wald isolated a substance found in the visual pigments of the eye and was able to show that this material was identical with Karrer s retinaldehyde [116-31-4] (5) (7). 

Oxygen compounds in crude oils are more complex than the sulfur types. However, their presence in petroleum streams is not poisonous to processing catalysts. Many of the oxygen compounds found in crude oils are weakly acidic. They are carboxylic acids, cresylic acid, phenol, and naphthenic acid. Naphthenic acids are mainly cyclopentane and cyclohexane derivatives having a carboxyalkyl side chain. 

The living character of the ROMP promoted by the initiator Ru(CHPh)(Cl)2 (PCy3)2 (Cy = cyclohexane) was tested with the synthesis of diblock, triblock, and tetrablock copolymers of norbornene derivatives carrying acetyl-protected glucose, [2,3,4,6-tetra-O-acetyl-glucos-l-O-yl 5-norbornene-2-carboxylate], A or maltose groups, [2,3,6,2/,3/,4/,6/-hepta-0-acetyl-maltos-1-O-yl 5-norbornene-2-carboxylate], B, shown in Scheme 41 [102]. The AB, ABA, and ABAB structures were prepared by sequential addition of monomers with narrow molecular weight distributions to quantitative conversions. 

Carboxyl and cyano substituent effects have been investigated in unsaturated and branched acyclic (79,417,418), cyclohexane (419), and certain piperidine (420) derivatives. A great variety of diesters and anhydrides have also been... 

Interestingly, cyclopentane and cyclohexane derivatives, which contain one or two hydroxyl, carbonyl, or carboxyl groups, degrade more readily in the environment than do their parent compounds. In fact, microorganisms capable of degrading of cycloalkanols and cycloalkanones are ubiquitous in environmental samples. 

Several cycloaddition reactions of 2,5-dihydrothiophene derivatives have been reported. Compounds possessing an enamine system undergo [2 + 2] cycloaddition with acetylene-dicarboxylic ester (Scheme 215) (77AHC(2l)253). Diels-Alder addition of the 2,5-di-hydrothiophene-3-carboxylic ester (557) with butadiene, followed by desulfurization, leads to the trisubstituted cyclohexane (558) (B-74MI31404). 

NAPHTHENIC ACIDS. The term naphthenic acid, as commonly used in the petroleum industry, refers collectively to all of the carboxylic adds present m crude oil. Naphthenic adds are classified as monobasic carboxylic acids of the general formula RCOOH, where R represents the naphthene moiety consisting of cyclopentine and cyclohexane derivatives. Naphthenic adds are composed predominantly of alkyl-substituted cycloaliphatic carboxylic adds, with smaller amounts of acyclic aliphatic (paraffinic or fatty) acids. Aromatic, okfinic. hydroxy, and dibasic acids are considered to be minor components. Commercial naphthenic aads also contain varying amounts of unsaponifiable hydrocarbons, phenolic compounds, sulfur compounds, and water. The complex mixture of adds is derived from straight-run distillates of petroleum, mostly from kerosene and diesel fractions. See also Petroleum. 

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