The major product obtained in the photo catalysed bromination of 2-methylbutane is:
1-bromo-2-methylbutane
1-bromo-3-methylbutane
2-bromo-3-methylbutane
2-bromo-2-methylbutane
2- methyl butane with bromine is photocatalyzed to give substitution products.
The order of substitution is
Therefore, option (4) is correct.