53126-10-6 73513-01-6 Spiro((10,12:19,22a)-dimethano-4H,5H,22aH-oxireno(8,9)(1,6,12)trioxacyclooctadecino(3,4-d)(1)benzopyran-11(10H),2'-oxirane)-2,14(1aH,17H)-dione, 19-acetyl-6,8a,11a,12,21,22-hexahydro-23-hydroxy-7,11a-dimethyl-