The synthesis of enantiomerically pure RPR107880 is described. The synthesis strategy is based on the use of the readily available and inexpensive (R)-(+)-pulegone.
An asymmetric synthesis of the key intermediate of RPR107880, a substancePantagonist, using a base-catalyzed Diels–Alder reaction of 3-hydroxy-2-pyrone and N-benzylmaleimide is described.