THE TITLE COMPOUND [SYSTEMATIC NAME: 9-ethyl-13-hy-droxy-14-methyl-2-(3,4,5-trimeth-oxy-6-methyl-tetra-hydro-2H-pyran-2-yl-oxy)-3,3a,5b,6,9,10,11,12,13,14,16a,16b-dodeca-hydro-1H-as-indaceno[3,2-d][1]oxacyclo-dodecine-7,15(2H,5aH)-dione], C(33)H(50)O(9), was obtained by hydrolysis of Spinosyn A. The fused cyclo-pentene ring adopts a twisted conformation, while the fused cyclo-hexene and cyclo-pentane rings are in envelope conformations with the same C atom at the flaps. In the crystal, mol-ecules are linked by O-H⋯O and C-H⋯O hydrogen bonds into a layer parallel to the ab plane.