The alkene shown reacts with $HBr$ . Counting constitutional isomers only (ignore stereoisomers), how many different alkyl bromides arise if both the product from the first-formed cation and the product after a single 1,2-hydride shift are counted? Give your answer as an integer.

Numerical answer type, tolerance 0.5.

Answer: 2

The alkene is vinylcyclopentane. Direct capture of the secondary cation gives (1-bromoethyl)cyclopentane, and one hydride shift from the ring CH gives the tertiary cation and 1-bromo-1-ethylcyclopentane. These are two constitutionally different bromides.

Practice Organic Reaction Mechanisms II: Electrophilic and Radical Reactions More on Rearranged products in electrophilic addition to drawn alkenes

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The alkene shown reacts with HBr. Counting constitutional isomers only (ignore stereoisomers), how many different alkyl bromides arise if both the product from the first-formed cation and the product after a single 1,2-hydride shift are counted? Give your answer as an integer.

Answer: 2

More questions on Rearranged products in electrophilic addition to drawn alkenes

The alkene shown reacts with $HBr$ . Counting constitutional isomers only (ignore stereoisomers), how many different alkyl bromides arise if both the product from the first-formed cation and the product after a single 1,2-hydride shift are counted? Give your answer as an integer.