3-(1,1-Dimethylethyl)-7-oxabicyclo(4.1.0)hept-3-ene-2,5-dione 7-Oxabicyclo(4.1.0)hept-3-ene-2,5-dione, 3-(1,1-dimethylethyl)- RN8843000 tert-Butylquinone oxide