3,6-Epoxy-2H,8H-pyrimido[2,1-b][1,3]oxazocine-8,10(9H)-dione,11-diazohexahydro-4-hydroxy-, (3R-(3.alpha.,4.alpha.,6.alpha.))- NSC70390 O6,5'-Cyclouridine, 5-diazo-2'-deoxy-