Halogenation Products
The halogenation process becomes more interesting as the complexity of the alkane increases. When methane is monohalogenated, there is only one product, halomethane.
Ethane also only produces a single product, as all its hydrogens are equivalent. Therefore, substituting any hydrogen with a halogen produces the same product.
With propane, two products arise as there are two different hygrogen environments, the methyls and methylene. The two methyl groups will produce the same product, 1-halopropane, while the methylene will lead to 2-halopropane..
The number of products is increased when chirality is considered. For instance, when butane is halogenated, even though there are only two different enivronments, labeled a and b below, there are three products as substitution at the b site will produce a chiral center, as there arefour different groups attached to the carbon. As mentioned earlier in this lesson, attack on the free radical can occur from either sideand therefore two products, the R and S forms of 2-halobutane will be porduced..
Test you luck, or knowledge, of how many total products you expect to be formed from the monochlorination of various alkanes.