(X= C02Et) boxylate (VIII) arid ethyl mesoxalat'e hydrate (IX) were derived. The pyrolysis of ethyl 1, S-hexadiene-1, 1, 3, 3, 4, 4, 6, 6-octacarboxylate (11), which also has the molecular formula C30H42016, reportedly'yields the aforementioned pyrone (IV) and the ozonolysis products are consistent with the hexadiene ester constitut'ion (11) for the permanganat'e oxidation product. Ethyl mesoxalate hydrate (IX) arises from eth. yl mesoxalate (VI), ...