Practical Synthesis of MDM2 Antagonist RG7388. Part 1: A Cu(II)-Catalyzed Asymmetric [3 + 2] Cycloaddition

An efficient asymmetric synthesis of MDM2 antagonist RG7388 is reported. The highly functionalized chiral pyrrolidine carboxamide was assembled via a Cu­(OAc)₂/(R)-BINAP catalyzed asymmetric [3 + 2] cycloaddition, which gave the exo and endo adducts in a ratio of 10:1, with high enantiomeric excess for the exo isomer. A one-pot hydrolysis and retro-Mannich/Mannich isomerization of the cycloaddition adducts in the presence of aqueous sodium hydroxide afforded RG7388 in high chemical and enantiomeric purities and 69% overall yield.