Question

Draw the major monobromination product formed by heating the following alkane with bromine.

Answer 1

The Bromination takes place at tertiary carbon when the alkane is treated with Br₂ in the presence of heat because the tertiary alkyl radical is more stable than secondary and primary alkyl radical.

By the action of heat, Br₂ breaks into 2Br radicals as shown below:

There are 8 possible sites for removal of hydrogen by bromine radical as shown below:

All the labeled sites contain one or more than one hydrogen groups.

The number of hydrogen attached to each site is as follows:

C-1 carbon has less number of hydrogen. Therefore, radical is form at C-1 carbon as shown below:

There is one methyl group at C-1 carbon and one methyl and one ethyl group at C-2 carbon of cyclopentane. After the removal of hydrogen, more substituted carbon forms stable radical but there must be hydrogen group present to form radical.

There are three possible shifts; one is methyl shift from C-2 to C-1 carbon that will result in following radical:

The suffix is ane
The IUPAC name of the given structure is 3-ethyl-2,2-dimethylhexane.