Showing structure for (1r,3r,13s,16s,17r,18s)-7,13,16,17-tetrahydroxy-2,2-dimethyl-10-oxapentacyclo[14.2.1.0³,¹².0⁴,⁹.0¹³,¹⁸]nonadeca-4,6,8,11-tetraen-14-one