(4R,5E,7Z,10Z,11aR)-6-formyl-10-methyl-3-methylene-2-oxo-2,3,3a,4,9,11a-hexahydrocyclodeca[b]furan-4-yl rel-2-methylpropanoate Acanthostral InChI=1/C19H22O5/c1-11(2)18(21)23-16-9-14(10-20)7-5-6-12(3)8-15-17(16)13(4)19(22)24-15/h5,7-11,15-17H,4,6H2,1-3H3/b7-5-,12-8-,14-9+/t15-,16-,17?/m1/s isobutyric acid 6-formyl-10-methyl-3-methylene-2-oxo-2,3,3a,4,9,11a-hexahydro-cyclodeca[b]furan-4-yl ester propanoic acid, 2-methyl-, (4R,5E,7Z,10Z,11aR)-6-formyl-2,3,3a,4,9,11a-hexahydro-10-methyl-3-methylene-2-oxocyclodeca[b]furan-4-yl ester