(2aR,3S,4S,4aR,5S,7aS,8S,10R,10aR,10bS)-10-Acetoxy-3,5-dihydroxy-4-[(1R,2S,6S,8R,9R,11S)-2-hydroxy-11-methyl-5,7,10-trioxatetracyclo[6.3.1.02,6.09,11]dodec-3-en-9-yl]-4,10a-dimethyldecahydro-1H-fu
ro[3',4':4,4a]naphtho[1,8-bc]furan-8-yl (2E)-2-methyl-2-butenoate