Exercise 7 | Delocalized π Systems and Dienes

Organic Chemistry 2 - Exercise 7

C can be synthesized from A in 2 steps. 
Draw the structure of B and explain the stereochemistry of this compound.
Give the synthetic condition of the second step.

First Step Explanation:

Steric Hindrance:
Formation of Endo product is not favored. Cycloaddition from the top.