8H,16H-7a,15a-(Epithiomethanoimino)-7H,15H-bisoxepino[3',4':4,5]pyrrolo[1,2-a:1',2'-d]pyrazine-7,15-dione, 5,13-bis(acetyloxy)-5,5a,13,13a-tetrahydro-18-thioxo-, (7aR,15aS)- AIDS-192893 AIDS192893