Dl. Comins et Jk. Saha, ASYMMETRIC-SYNTHESIS OF A KEY CAMPTOTHECIN INTERMEDIATE FROM 2-FLUOROPYRIDINE, Tetrahedron letters, 36(44), 1995, pp. 7995-7998
The DE ring camptothecin intermediate II was prepared enantioselective
ly in six steps from 2-fluoropyridine using a pyridine ''halogen-dance
'' reaction.