Alkanes Wurtz synthesis

A long established method for the preparation of alkanes involves heating an alkyl halide with sodium metal (the Wurtz synthesis). 

The Wurtz synthesis is a method of producing alkanes by the reaction of all l... 

In the Wurtz synthesis, a complex alkane is produced from smaller ones. Hence methane cannot be produced in this way. If different aUqd halides are used in the Wurtz synthesis, three different alkanes can be formed. For this reason, this method is more useful for alkanes which have even numbers of carbon atoms. 

The symmetrical Wurtz coupling has been found to give particularly good yields in the case of the higher alkane homologues. Selected illustrative examples (hexane, octane, decane and dodecane) are to be found in Expt 5.7. A related reaction is to be found in the synthesis of hexa- 1,5-diene (Expt 5.7, cognate preparation), which illustrates the symmetrical coupling of two molecules of allyl iodide by the action of sodium metal. 

Although it s one of organic chemistry s classic reactions, the Wurtz reaction is seldom used for alkane synthesis. Alkanes are typically much more conveniently obtained from petroleum, natural gas, and the reduction of fatty acids. The Wurtz reaction is most valuable for specialized applications, particularly for closing cyclopropane rings, as in the synthesis of bicyclo[1.1.0]butane, shown below ... 

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