Tilivalline (1a), a metabolite from Klebsiella pneumoniae var. oxytoca, and its derivatives 1 have been efficiently and stereoselectively synthesized from diphenyl phosphorazidate, the 2-oxazoline 2, the L-proline derivatives 5, and indole; the key step is a Mannich type intramolecular cyclization accompanied with completely stereoselective introduction of indole. Furthermore, 11-substituted 5H-pyrrolo [2, 1-c][1, 4] benzodiazepin-5-ones (16) ...