The structure elucidations of new fungal products CP-225,917 and CP-263,114 are described. The structures, including relative stereochemistry, were established using a variety of analytical data and extensive NMR analysis. The compounds possess a bicyclo[4.3.1]deca- 1,6-dien-10-one system in conjunction with a maleic anhydride moiety, a gamma-lactol, and two alkenyl side chains. They are related to nonadrides, and their biosynthetic origins are proposed. The producing organism also yields zaragozic acid A, and both zaragozic acids and compounds CP-225,917 and CP-263,114 appear to be derived from the condensation of oxaloacetic acid and the corresponding monocarboxylic acid.