Derived from Arylpyruvic Acids

Under these conditions 2-phenyl-4-(3-methoxy-4 -benzyloxybenzal)-5-oxazolone gives 3-methoxy-4-benzyloxypyruvic acid in 90% yield (ninety-six-hour reaction time) 2-phenyl-4-(3, 4 -methylenedioxyben-zal)-5-oxazolone gives the pyruvic acid in 85% yield (reaction time not given) the azlactones derived from vanillin, m-hydroxybenz deh5 de, and p-hydroxybenzaldehyde give no arylpyruvic acid. 

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