(11S,11aS)-allyl 11-((tert-butyldimethylsilyl)oxy)-2-(4-fluorophenyl)-8-(3-iodopropoxy)-7-methoxy-5-oxo-11,11a-dihydro-1H-benzo[e]pyrrolo[1,2-a][1,4]diazepine-10(5H)-carboxylate