Efficient and stereoselective syntheses of DAB-1 and d-fagomine via chiral 1,3-oxazine

The concise, stereocontrolled syntheses of DAB-1 and d-fagomine were achieved utilizing chiral oxazine. The key features in these strategies are the stereoselective intramolecular oxazine formation catalyzed by palladium(0), and pyrrolidine and piperidine formation by catalytic hydrogenation of oxazine.