glaucolide B

(1aR,5R,7S,10aS,10bR)-5,7-Diacetoxy-8-acetoxymethyl-2,3,6,7,10a,10b-hexahydro-1a,5-dimethyloxireno[9,10]cyclodeca[1,2-b]furan-4,9(1aH,5H)-dione