2-Methoxy-4-oxo-1-(2-propenyloxy)-2,5-cyclohexadiene-1-carboxylic acid methyl ester C??? ??, ??, ??

2-Methoxy-4-oxo-1-(2-propenyloxy)-2,5-cyclohexadiene-1-carboxylic acid methyl ester ?? ?? ? ???

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2-Methoxy-4-oxo-1-(2-propenyloxy)-2,5-cyclohexadiene-1-carboxylic acid methyl ester ?? ??