Solution: In the presence of a Lewis acid, compound  1 rearranges, via intermediate 2, to afford compound 3. (a) Draw curved arrows showing how 1 is transformed into 2. Note that the Lewis acid has been left out for simplicity. 

Problem

In the presence of a Lewis acid, compound  rearranges, via intermediate 2, to afford compound 3

(a) Draw curved arrows showing how is transformed into 2. Note that the Lewis acid has been left out for simplicity.