Furan
(1aS,4S,4aS,5aR,5bS,8aR,8bS)-5a,7,7-trimethyloctahydrocyclopropa[4,5]oxireno[6,7]indeno[5,6-c]furan-4-ol
{(1aR,8R,8aS,8bR)-6-[(furan-2-ylmethyl)amino]-8a-methoxy-5-methyl-4,7-dioxo-1,1a,2,4,7,8,8a,8b-octahydroazireno[2',3':3,4]pyrrolo[1,2-a]indol-8-yl}methyl carbamate