Cycloalkyl compounds

The data of Friswell et al. [51] for the reactions of the cycloalkyl bromides with sodium at 520°K can be compared with the competitive method data [35, 37] for the reaction of cycloalkyl chlorides with potassium at the same temperature (see Table 4). 

The variation in rate coefficients can be considered in terms of the relief of internal strain in the transition state and also in terms of the sequence of hybridisation change reflecting the change in rates 

Emovon and Ojo [36] have extended their studies to some bicyclic chlorides and have obtained the following sequence of rates relative to reaction of potassium atoms with cyclopentylchloride at 520°K. 

The results are interpreted in terms of steric and hybridization effects. 

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Table IX shows the corresponding effects in solvolysis of cycloalkyl compounds. The inclusion of cyclopropylmethyl benzenesulfonate...

Name the compound as a cycloalkyl substituted alkane if the substituent has more carbons than the ring... 

Cycloalkylation of aromatic compounds with 1,4- or 1,3-glycols ia the presence of aluminum chloride leads to the formation of derivatives of tetrahydronaphthalene oriadane, respectively (55). 

Amines are derivatives of ammonia in which one or more of the hydrogens is replaced with an alkyl, aryl, cycloalkyl, or heterocycHc group. When more than one hydrogen has been replaced, the substituents can either be the same or different. Amines are classified as primary, secondary, or tertiary depending on the number of hydrogens which have been replaced. It is important to note that the designations primary, secondary, and tertiary refer only to the number of substituents and not to the nature of the substituents as in some classes of compounds. 

Appllca.tlons. MCA is used for the resolution of many classes of chiral dmgs. Polar compounds such as amines, amides, imides, esters, and ketones can be resolved (34). A phenyl or a cycloalkyl group near the chiral center seems to improve chiral selectivity. Nonpolar racemates have also been resolved, but charged or dissociating compounds are not retained on MCA. Mobile phases used with MCA columns include ethanol and methanol. 

Transesterification has become a convenient method for synthesi2ing high alkyl, aryl, or alkyl aryl carbonates. Fiber- and film-forming polycarbonates are produced by transesterifying dialkyl, dicycloalkyl, or diaryl carbonates with alkyl, cycloalkyl, or aryl dihydroxy compounds (62). 

Dimethyl sulfoxide reacts with trifluoroacetic anhydride at low tempera ture to give a complex that is an efficient reagent for the oxidation of alcohols to carbonyl compounds [40 41] This reagent can be used to oxidize primary and secondary aliphatic alcohols, cycloalkyl alcohols, and allylic, homoallylic, ben-zylic, acetylenic, and steroidal alcohols (equation 19)... 

When the ring contains fewer carbon atoms than an alkyl group attached to it, the compound is nfflned as an alkane, and the ring is treated as a cycloalkyl substituent ... 

At higher temperatures the mixture of 10 and methyl vinyl ketone yields the 1,4-carbocyclic compound as described previously. Methyl isopropenyl ketone (5), ethyl acetylacrylate (d), 2-cyclohexenone (21), and 1-acetyl-1-cyclohexene (22) also undergo this type of cyclization reaction with enamines at higher temperatures. This cycloalkylation reaction occurs with enamines made of strongly basic amines such as pyrrolidine, but the less reactive morpholine enamine combines with methyl vinyl ketone to give only a simple alkylated product (7). Chlorovinyl ketones yield pyrans when allowed to react with the enamines of either alicyclic ketones or aldehydes (23). 

Phthalic anhydride also shows the ability to inhibit thermal destruction of polyolefins [21]. Among the organometallic compounds may be quoted organotin compounds R2Sr(OR )2, where R2 means alkyl, aryl, or cycloalkyl OR means alkoxyl, acyl, or R2Sn(CH2COORi)2, where Rj—Ci—Cm means alkyl, allyl, or benzyl Ro represents chloro-, mono-, or triorga-notin mercaptans [22,23]. 

Count the number of carbon atoms in the ring and the number in the largest substituent chain, (f the number of carbon atoms in the ring is equal to or greater than the number in the substituent, the compound is named as an alkyl-substituted cycloalkane. If the number of carbon atoms in the largest substituent is greater than the number in the ring, the compound is named as a cycloalkyl-substituted alkane. For example ... 

TgRs compounds where R is a cycloalkyl or substituted aryl group... 

In Method 2, described by Rule A-31, the saturated cyclic parent is named as a polycyclo-[.. jalkane. The alkane name identifies the total number of carbon atoms in the ring system. The names bicyclo, tricyclo, tetracyclo, etc. identify parent compounds of two, three, four, etc. rings. Double bonds in the ring are identified by names such as w-alkenc, ,/w-alkadicne, where the n and m give the position of the double bond. Substituents consist of alkyl, cycloalkyl, phenyl, etc. radicals. 

Aromatic compounds, 13 108-109 13 680. See also Aromatics acylation of, 12 173-181 amination of, 12 184 arylation of, 12 170-171 Cycloalkylation of, 12 169 in diesel fuel, 12 425 formylation of, 12 178 Friedel-Crafts acylation of, 12 174 Friedel-Crafts alkylation of, 12 164 nitration of, 12 182-183 oxidative coupling of, 19 654 sulfonation of, 12 181 sulfonation reagents for, 23 521-524 Aromatic-containing polymers, sulfonation of, 23 535-536... 

In West Germany pyridazinium compounds as represented by formula (120, R1 = halogen, alkyl, aryl R2 = H, alkyl R3 = substituted amino R4 = substituted alkyl, cycloalkyl) have been claimed as antibacterial agents [338]. In Australia, mercapto derivatives of several nitrogen heteroaromatics including pyridazine-derived compounds (121, R = CONH2, CH2NMe2) have been prepared in a search of amplifiers of phleomycin [339] however, only low activity has been observed in this series. 

So far, the formation of cyclic alkoxyallenes bearing an exocydic or endocyclic allenyl unit has been less developed. Several examples with this structural feature are described as unstable compounds or highly reactive intermediates [32-35]. However, in the 1990s, Lavoisier-Gallo and Rodriguez demonstrated a useful one-pot protocol for the synthesis of 2-vinylidenedihydrofurans such as 29 involving a tandem C-O cycloalkylation of stabilized carbanion intermediates 28 as crucial step (Scheme 8.10) [36, 37]. 

Methylenesulphones are more acidic than the simple esters, ketones and cyano compounds and are more reactive with haloalkanes [e.g. 48-57] to yield precursors for the synthesis of aldehydes [53], ketones [53], esters [54] and 1,4-diketones [55] (Scheme 6.4). The early extractive alkylation methods have been superseded by solidtliquid phase-transfer catalytic methods [e.g. 58] and, combined with microwave irradiation, the reaction times are reduced dramatically [59]. The reactions appear to be somewhat sensitive to steric hindrance, as the methylenesulphones tend to be unreactive towards secondary haloalkanes and it has been reported that iodomethylsulphones cannot be dialkylated [49], although mono- and di-chloromethylsulphones are alkylated with no difficulty [48, 60] and methylenesulphones react with dihaloalkanes to yield cycloalkyl sulphones (Table 6.5 and 6.6). When the ratio of dihaloalkane to methylene sulphone is greater than 0.5 1, open chain systems are produced [48, 49]. Vinyl sulphones are obtained from the base-catalysed elimination of the halogen acid from the products of the alkylation of halomethylenesulphones [48]. 

Oxygen is one of the five (C, H, N, O, and S) major elements in resids and asphalt, although the level rarely exceeds 1.5% by weight. Many petroleum products do not specify a particular oxygen content, but if the oxygen compounds are present as acidic compounds such a phenols (Ar-OH) and naphthenic acids (cycloalkyl-COOH), they are controlled in different specifications by a variety of tests. 

The electrophilic reactivity of lithium carbenoids (reaction b) becomes evident from their reaction with alkyl lithium compounds. A, probably metal-supported, nucleophilic substitution occurs, and the leaving group X is replaced by the alkyl group R with inversion of the configuration . This reaction, typical of metal carbenoids, is not restricted to the vinylidene substitution pattern, but occurs in alkyl and cycloalkyl lithium carbenoids as well ". With respect to the a-heteroatom X, the carbenoid character is... 

A-Boc-4-tosyloxypiperidine (161) undergoes, upon (—)-sparteine-mediated deprotonation, cycloalkylation to form via the lithium compound 162 the l-azabicyclo[3.1.0]hexane 163. 163 is subsequently deprotonated at the bridged-head carbon atom and lithium compound 164 is trapped by silylation the yield of 165 and the e.r. are low (equation 37)" " . 

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