Alicyclic hydrocarbons double bonds

Although it is possible to conceive of alicyclic hydrocarbons containing more than a triple bond or two double bonds in the carbocyclic ring, such ring structures are usually either unstable or have transient existence. 

Peroxyl radicals can undergo various reactions, e.g., hydrogen abstraction, isomerization, decay, and addition to a double bond. Chain propagation in oxidized aliphatic, alkyl-aromatic, alicyclic hydrocarbons, and olefins with weak C—H bonds near the double bond proceeds according to the following reaction as a limiting step of the chain process [2 15] ... 

Allyltriisopropylsilane, 11 Alicyclic hydrocarbons Three-membered rings By cyclopropanation of carbon-carbon double bonds... 

It is not very likely that the influence of a double bond extends far over a chain of carbon atoms. For example, it is difficult to believe that a double bond at one end of the cetene-1 molecule containing 16 carbon atoms has an effect on hydrogen exchange at its other end. It is more likely that complete hydrogen exchange in alkene molecules and unsaturated alicyclic hydrocarbons is due to multiple bond migrations, i.e. isomerization of the hydrocarbon. 

It would be interesting to carry out analogous experiments with unsaturated alicyclic hydrocarbons whose side-chain is separated from the ring by a tertiary carbon atom. It would also be desirable to measure the kinetics of hydrogen exchange for non-equivalent atoms in alkene molecules, and to compare the rates of deuterium exchange and isomerization, and also the rates of all these processes in hydrocarbons of similar composition with double and triple bonds, and so on. 

We have already acknowledged our intent to use relevant estimation approaches to enthalpies of vaporization and sublimation to maximize the usefulness of the data available. That dienes and polyenes have multiple double bonds that are potentially hydrogenatable to the totally saturated aliphatic or alicyclic hydrocarbons allows the employment of two other assumptions. The first assumption argues that the enthalpy of hydrogenation, AHn measured in a nonpolar solvent is essentially equal to that which would be obtained in the gas phase. The second assumption, implicitly employing the first, legitimizes the use of estimation techniques and even molecular mechanics to derive the enthalpy of formation of the totally saturated species. From this last number, the enthalpy of formation of the unsaturated diene or polyene of interest can be derived by equation 3 and simple arithmetic. 

Cycloolefin. An alicyclic hydrocarbon having two or more double bonds, e.g., the very reactive and... 

There are a number of classifications analogous to those of hydrocarbons (1) paraffinic or simple alcohols, whose formula may be represented as CnHa+1 (2) olefinic or fatty alcohols that contain one or more double bonds (3) alicyclic alcohols, closed-ring structures that may or may not contain a double bond, e.g., cyclohexanol (4) aromatic alcohols in which the hydroxyl group is attached to a benzene... 

The toxicities of aliphatic and alicyclic hydrocarbons in humans and animals are very low. The gaseous compounds are aU nontoxic and are simple asphyxiants. The presence of a double or triple bond in the molecule or cyclization does not enhance the toxicity of the hydrocarbons, especially the lower ones. Only at very high concentrations in air are these gases narcotics. The higher hydrocarbons, which are liquid at ambient conditions, are also of low toxicity, producing anesthetic effects only at high doses. 

Detection of certain types of compounds (for example, of an aromatic skeleton). If the compound trasmits radiation (b < 1) between 220 and 800 nm, it may well be an aliphatic or alicyclic hydrocarbon, amine, nitrile, alcohol, ether, alkyl chloride, or alkyl fluoride, but the presence of conjugated double bonds, the carbonyl group, nitro group, bromine, or iodine is excluded. The detection of the aromatic nucleus in an unknown sample is carried out by measuring the absorption in the ultraviolet region of ethanolic, cyclohexane, or /i-hexane solutions of various concentrations (10 -10 mole/liter). 

The Ring System and Its Possibilities tor Isomerism. According to systematic chemical nomenclature, cholesterol is a derivative of cyclopentanoperhydrophenanthrene. This alicyclic, saturated hydrocarbon (without double bonds or aromatic character) bears the trivial name sterane. The C atoms are numbered in the manner indicated. 

Hydrocarbons. Compounds consisting of carbon and hydrogen. The number of such compounds is immense and they may be classified into aliphatic (alicyclic) and aromatic (cyclic) compounds. In the former class, the principal carbon atoms are arranged in chains, while in the latter class they are arranged in one or several rings. Hydrocarbons may also be divided into saturated —in which all four valences of C are satisfied, and unsaturated —in which there are one or more double or triple bonds between carbon atoms... 

Cycloalkanes - Saturated monocyclic hydrocarbons (with or without side chains). See alicyclic compounds. Unsaturated monocyclic hydrocarbons having one endocyclic double or one triple bond are called cycloalkenes and cycloalkynes, respectively. [5]... 

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