Methyl (1aR,5S,8S,10R,22aR)-5-tert-butyl-14-methoxy-3,6-dioxo- ? ? ? ? ? ? ? ? ?1,1a,3,4,5,6,9,10,18,19,20,21,22,22a-tetradecahydro-8H-7,10- ? ? ? ? ? ? ? ? ?methanocyclopropa[18,19][1,10,3,6]dioxadiazacyclononadecino[11,12-b]quinoxaline-8-carboxylate
