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Can you explain the mechanism of the reaction (step-by-step) by which the alkene + HBr is changed into an alkyl halide?

Answer 1

The mechanism involves two steps.

In Step 1, the π electrons in the double bond attack the HBr, producing an intermediate carbocation and leaving a negative bromide ion.

In Step 2, the bromide ion then joins to the positive carbon of the carbocation.

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Answer 2

Carter Allen

The reaction involves electrophilic addition. Here's the step-by-step mechanism:

Initiation: Homolytic cleavage of the Br-Br bond in HBr, forming two radicals.
Propagation - Step 1: One of the bromine radicals attacks the alkene, forming a bromine molecule and a primary alkyl radical.
Propagation - Step 2: The alkyl radical reacts with another HBr molecule, generating the alkyl bromide and regenerating the bromine radical.
Termination: Various reactions between radicals, leading to the formation of stable products.

This process results in the addition of HBr across the double bond, leading to the formation of an alkyl bromide.

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Answer from HIX Tutor

When evaluating a one-sided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.