In the presence of a small amount of bromine, cyclohexene undergoes the following lightpromoted reaction:

(a) Propose a mechanism for this reaction.

(b) Draw the structure of the rate-limiting transition state.

(c) Use the Hammond postulate to predict which intermediate most closely resembles this transition state.

(d) Explain why cyclohexene reacts with bromine much faster than cyclohexane, which must be heated to react.

Transcribed Image Text:

Br hv + trace Br, + HBr cyclohexene 3-bromocyclohexene