Azirino(2',3':3,4)pyrrolo(1,2-a)indole-4,7-dione, 6-amino-8-(((aminocarbonyl)oxy)methyl)-1-(5-((2,5-dioxo-1-pyrrolidinyl)oxy)-1,5-dioxopentyl)-1,1a,2,8,8a,8b-hexahydro-8a-methoxy-5-methyl-, (1aS-(1aalpha,8beta,8aalpha,8balpha))-