Chapter 11, Problem 51P

Compound A was converted to compound B by the sequence shown. It is likely that the first step in this sequence gives two isomeric products having the molecular formula ${\text{C}}_{10}{\text{H}}_{15}{\text{BrO}}_2$, and both of these give compound B in the second step.

(a) Suggest reasonable structures for the two isomers of ${\text{C}}_{10}{\text{H}}_{15}{\text{BrO}}_2$ formed in the first step.

(b) Give a mechanistic explanation why both isomers give the same product in the second step.