Olefins can be halogenated in the allylic position by number of reagents of which N-bromo succinimide (NBS) is the most common. When this reagent is used the reaction is known as WohlZiegler bromination. Other N-bromoamides have also been used. To a much lesser extent allylic chlorination has been carried out with N-chloro-succinimide. N-Chloro-N-cyclohexyl benzene sulphonamide or t-hypochlorite when the allylic radical intermediate is unsymmetrical allylic rearrangement takes place so that the mixture of both possible products is obtained.
`CH_3 - CH_2 -CH = CH_2underset(hv)overset(NBS)(to) CH_3 - CH = CH - CH_2 - Br + CH_3 - undersetoverset(|)(Br)(C ) - CH = CH_2`
NBS is also a highly regioselective brominating agent at other positions, including positions a to a carbonyl group.
Which of the following is allylic chlorinating agent ?

Options

A. N-Chlorosuccinimide
B. Chloro-N-cyclohexyl benzene sulphonamide
C. `SO_2Cl_2//hv`
D. All of these

Answer

D

Explanation

Conceptual