First and Highly Stereoselective Synthesis of Both Enantiomers of Octahydroindole-2-phosphonic Acid (OicP)

We report the first stereoselective synthesis of (2R,3aR,7aR)- and (2S,3aS,7aS)-octahydroindole-2-phosphonic acid 2 (OicP derivatives). The key points are the highly diastereoselective synthesis of cis-fused bicyclic (3aR,7aR)- and (3aS,7aS)-pyrrolidin-2-ones 4 through a dynamic kinetic resolution of racemic γ-keto acid (±)-5 with (R)- and (S)-phenylglycinol via Meyers' bicyclic lactams, and the highly diastereoselective addition of trimethyl phosphite to the N-acyliminium ions 3 obtained from 4.