Alkanes parent hydrides

In the other method, the ending -ane is changed to -ene or -yne to indicate the presence of a double or triple bond. This is used for alkanes and mono- and polycyclic alkane parent hydrides. In alkanes and cycloalkanes, the change of the -ane ending to -ene or -yne indicates the presence of one double or triple bond. Multiplicative prefixes di-, tri-, tetra-, etc. are used to signal the multiplicity of unsaturated bonds. Locants placed immediately in front of the endings -ene and -yne are used as needed. 

The names of unbranched alkanes are of the utmost importance because these alkanes are the parent hydrides used to name all aliphatic molecules, i.e. molecules having a carbon-chain skeleton. 

General. Continuous-chain alkanes are the sole parent hydrides for all compounds, the skeleton of which is composed of chains. Cyclic parent hydrides are more diverse. In nomenclature, they are classified according to their structure as carbo-cycles (composed of carbon atoms only) and heterocycles (composed of carbon atoms and other atoms, such as N, O and Si). They are also classified as saturated and unsaturated. Saturated cycles have the maximum number of hydrogen atoms attached to every skeletal atom, as judged by a prespecified valence unsaturated cycles have fewer hydrogen atoms and multiple bonds between pairs of atoms. 

For comparison, only a few dozen alkanes are designated as parent hydrides. Over 73 000 rings and ring systems are mancudes and about 10 000 are carbocycles. 

The reactions proposed for the formation of the labeled products in the triton transfer to ethane, propane, butane and isobutane are illustrated in Fig. 6. The formation of the parent tritiated alkane was ascribed, without invoking the intervention of long-lived protonated ions, to a mechanism involving the protonation reaction (48), followed by the fragmentation process (50b) and by a thermoneutral hydride-ion transfer from the unlabeled alkane to the tritiated alkyl ion ... 

The parent carbon hydride, on the other hand, is the fully covalent methane, CH4, the simplest of thousands of alkanes of general formula C 2n+2- Although others had prepared the corresponding silanes before, Alfred Stock, in 1916, was the first to carry out a systematic investigation of them with the aid of his vacuum hne and its mercury-activated stopcocks and valves. In the absence of air and water, he found that the metal silicides (as he had the borides, see p. 400) reacted with various acids, as represented in Equation (15.3) ... 

The Baiton-McCombie reaction describes the overall reduction of a 1°, 2°, or 3° alcohol (1) to the parent alkane (3), effectively replacing -OH with -H. Reduction is achieved via pre-activation of the hydroxyl group as its thiocarbonyl derivative (2) followed by reaction with a reducing agent such as tributyltin hydride. The reductive process involves a radical-mediated transformation. 

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