Cyclopentadiene reacts with maleic anhydride at room temperature. Which of the following statements are correct? Select all that apply.

1. AThe endo adduct is chiral and is formed as a racemate
2. BThe endo adduct is the kinetically favoured major product
3. CThe reaction is a concerted [4+2] cycloaddition in which both new bonds form on the same face of each component
4. DThe two carbonyl groups of the anhydride end up cis to each other, fixed by the geometry of the dienophile