CC1(C)[C@@H](Br)CC[C@]2(C)O[C@@H](C3=C(O)C(=O)OC3)C[C@@H]12 3-[(2R,3aS,5S,7aS)-5-bromo-4,4,7a-trimethyl-2,3,3a,5,6,7-hexahydro-1-benzofuran-2-yl]-4-hydroxy-2H-furan-5-one