Cyclic alkanes ethers

Typical acrylic monomers contain either the acrylate functionality (structure 8) or the methacrylate functionality (structure 9), where R can be aromatic or aliphatic, and also contain linear, branched, or cyclic alkanes, ethers, or esters (see Acrylic Ester Polymers). 

Pell and Pilcher have tabulated the strain energies of cyclic alkanes, ethers, imines, and sulfides (Table 12), which all decrease with ring size in the order 3 > 4 > 5 > 6. Thus if the same fraction of the strain energy is always developed in the transition state, it would be expected that if this were the only controlling factor the rates of reactions that form rings of this type would be in the order 6 > 5 > 4 > 3. 

Further, a large number of examples with simple alkyl substituents [168, 171, 176-184], cyclic alkanes [185], aryl substituents [177, 186-192], olefmic substituents [78, 177, 193-196], deuterated compounds [172], thioether groups [171], ester groups [197], orthoesters [198, 199], acetals [168, 182, 200-204], silyl-protected alcohols [198, 205-211], aldehydes [212], different heterocycles [213-217], alkyl halides [218, 219] and aryl halides [192, 220-223] have been reported. A representative example is the reaction of 92, possessing a free hydroxyl group, an acetal and a propargylic ether, to 93 [224] (Scheme 1.40). 

The estimates of the RSE for small cyclic alkanes, cyclo-olefins, and cyclic ethers using all three reactions are listed in Table 3.21. The failure of the isodesmotic reaction is readily apparent by examining the RSE of the cyclic alkanes. For the rings having five or more carbon atoms, the isodesmic method predicts that there is no strain energy. Rather, it predicts that these cyclic species are more stable than their acyclic counterparts. The homodesmotic and GE reactions, which are identical for the cyclic alkanes, provide RSEs in excellent agreement with CRSE estimates. 

Scope of the Problem. Petroleum hydrocarbons are the principal components in a wide variety of commercial products (e.g., gasoline, fuel oils, lubricating oils, solvents, mineral spirits, mineral oils, and crude oil). Because of widespread use, disposal, and spills, environmental contamination is relatively common. It is important to understand that petroleum products are complex mixtures, typically containing hundreds of compounds. These include various amounts of aliphatic compounds (straight-chain, branched-chain, and cyclic alkanes and alkenes) and aromatic compounds (benzene and alkyl benzenes, naphthalenes, and PAHs). In addition, many petroleum products contain nonhydrocarbon additives such as alcohols, ethers, metals, and other chemicals that may affect the toxicity of the mixture. 

Substitution of extra-annular hydrogen atoms of the cyclic mono-ethers seems to have the same effect on the heat of polymerization as it does in the case of the cyclo-alkanes. Thus, for the 3,3-disubstituted-l-oxacyclobutanes the heats of polymerization are less than for the parent compound, trimethyiene oxide. 

A. Yan, R. Zhang, M. Uu, Z. Hu, M. A. Hooper, and Z. Zhao, Comput. Chem., 22, 405 (1998). Large Artificial Neural Networks Applied to the Prediction of Retention Indices of Acyclic and Cyclic Alkanes, Alkenes, Alcohols, Esters, Ketones, and Ethers. 

An alternative way to form meso-substituted dipyrrolyl alkanes was discovered by Yadav et al, using InBrs (5 mol%) to catalyze the reaction between pyrroles and cyclic enol ethers or enecarbamates [133] (Figure 8.57). InCl3 (10mol%) was also reported to be equally effective. 

The key initiation step in cationic polymerization of alkenes is the formation of a carbocationic intermediate, which can then interact with excess monomer to start propagation. We studied in some detail the initiation of cationic polymerization under superacidic, stable ion conditions. Carbocations also play a key role, as I found not only in the acid-catalyzed polymerization of alkenes but also in the polycondensation of arenes as well as in the ring opening polymerization of cyclic ethers, sulfides, and nitrogen compounds. Superacidic oxidative condensation of alkanes can even be achieved, including that of methane, as can the co-condensation of alkanes and alkenes. 

Reactions of alkanedicarboxylic acids with sulfur tetrafluoride afford, in general, mixtures of bis(trifluorQmethyI)allcanes, cyclic 0(,a,a, a -tetrafluoro ethers, linear bis(pentafluoroalkyl) ethers, and polyfluoroethers The cyclic ethers constitute the major products of the reactions with alkane-1,2 dicarboxyhc acids, they are also formed in the reactions with alkane-1,3-dicarboxylic acids but not with 1,1- nor 1,4-dicarboxylic acids [211] (equation 105)... 

An illustration of the tendency of alkane 1,2- and alkane-1,3-dicarboxylie acids to a ring closure during the reaction with sulfur tetrafluoride is the reaction of propane-1,2,3-tricarboxylie acid The corresponding six- and five-membered cyclic ethers are formed in a 1 4 ratio [211] (equation 106)... 

The alkanephosphonic acid dichlorides obtained by these methods are converted with amines, with all reactions carried out in solvents such as acetone, benzene, or diethyl ether at 10°C with triethylamine as HC1 captor. The conversion runs quantitatively followed by a purification with the help of column chromatography with chloroform/methanol in a ratio of 9 1 as mobile phase. The alkanephosphonic acid bisdiethanolamides could be obtained as pure substances with alkane residues of C8, C10, C12, and Ci4. The N-(2-hydroxyethane) alkanephosphonic acid 0,0-diethanolamide esters were also prepared in high purity. The obtained surfactants are generally stable up to 100°C. Only the alkanephosphonic acid bismonomethylamides are decomposed beneath this temperature forming cyclic compounds. 

The deoxygenation of cyclic ethers means the cleavage of both C-O bonds and leads to alkenes or alkanes depending on the hydrogenating activity of the catalyst (Scheme 4.2). 

Alkyl groups of compounds other than alkanes can be regioselectively functionalized using C-H activation chemistry. For example, acyclic and cyclic ethers can be activated by Ir(m) complexes to yield carbene complexes (Equation (25)).35... 

The hydrogen donors vary widely from heteroatom-containing compounds such as alcohols, amines, acids and cyclic ethers to hydrocarbons such as alkanes (Table 20.1). The choice of donor is largely dependent on several issues ... 

The insertion reaction chemistry of the well-known germylene Ge [CH(Si M03)3)2 50 is very diverse.154 323-328 This species inserts readily into the C-H bonds of mono- and dinitrile substrates (Scheme 47),154 the C-H bonds of ethers and alkanes in the presence of Phi (Scheme 48),323 the C-H bonds of ketones in the presence of MgCE (Scheme 49) and the O-H bonds of the tautomer enols in the absence of MgCl2 (Scheme 50),324 and the C-H bonds of diketones resulting in cyclic products (Scheme 51). 

The interdigital secretion of the red hartebeest, A. b. caama, consists of fewer compound classes. It contains a few alkanes and short-chain, branched alcohols, fatty acids, including a few of the higher fatty acids up to octadecanoic acid, an epoxide and the cyclic ethers, rans-(2 ,5.R)-furanoid linalool oxide 23, as-(2JR,5S)-furanoid linalool oxide 24 and ds-(2S,5i )-furanoid linalool oxide 25 (Fig. 5) in a ratio of 2.5 1 1.5 respectively [138]. From the point of view that many of the constituents of the interdigital secretion of this animal are probably of microbial origin, it is interesting that cis- and trans- furanoid linalool oxides have also been found in castoreum [77]. 

Calvo, E., Brocos, P., Bravo, R., Pintos, M., Amigo, A., Roux, A.H., and Roux-Desgranges, G. Heat capacities, excess enthalpies, and volumes of mixtures containing cyclic ethers. 1. Binary systems 1,4-dioxane -r n-alkanes, J. Chem. Ene. Data, 43(1) 105-111, 1998. 

The products of the electrochemical perfluorination of aromatic and heteroaromatic compounds are the corresponding perfluorinated cyclic and heterocyclic alkanes.28 and also per-fluorinated derivatives of the heteroaromatic compounds. Perfluorocyclohexane is the principal product from the electrochemical fluorination of benzene and fluorobenzene. Chloro derivatives of perfluorocyclohexane are produced from chlorobenzenes. Anisoles give fully saturated per-fluoro ethers, together with cleavage products. Extensive cleavage is observed in the fluorination of benzenethiols. Chloropyridines, fluorocarbons and sulfur hexafluoride or nitrogen trifluoride are characteristic byproducts from the above scries of reactions. 

Saturated alkane-1,2-carboxylic acids and alkane-1,3-carboxylic acids give, in general, three types of products bis(trifluoromethyl)alkancs, cyclic a,a,a, a -tetrafluoro ethers and linear bis(pentafluoroalkyl) ethers. The 1,2-dicarboxylic acids, succinic and halosuccinic acids, give as the main products the cyclic ethers 6, derivatives of tetrahydrofuran, in ca. 30-50% yield, but from 1,3-dicarboxylic acids the yields of the corresponding six-membered ethers 9 are 16%.118... 

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