Question

The carbon atoms at which bromination will take place are
NBS/hv
CCI
A) 1.2 and 3
B) 4 and 5
C) 1,3, 4 and 5
D) 1, 3 and 4​

Answer 1

Answer:

Bromination will take place at 1,3,4.

D is the correct option.

Answer 2

The bromination will take place at carbon numbers 1, 3, and 4 of the given compound in the presence of NBS/ hv.

• NBS stands for N- Bromosucccinimide. This is a chemical compound that helps in allylic substitution.
• NBS help in the replacement of hydrogens on carbon which is adjacent to a double bond with bromine.
• In the given compound, 1 and 2 carbon are allylic carbons as they are adjacent to the double bonds.
• Also, the carbon at the 5th position is allylic because it is also adjacent to a double-bonded carbon atom.
• The NBS will act on these three carbon atoms in presence of light and CC$l_{4}$ and bromination will occur.