6,7-Dihydroxy-3-(4-methoxyphenyl)-4-benzopyrone → 3-(4-Methoxyphenyl)-3,4-dihydro-2H-1-benzopyran-6,7-diol

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Reaction Steps

Fifteen grams of texasin (6,7-dihydroxy-3-(methoxyphenyl)chromone) were dissolved and partially suspended in 500 ml of ethanol and hydrogenated at normal pressure and room temperature using 10% palladium/charcoal as a catalyst under addition of 20 drops of concentrated sulfuric acid. The catalytic hydrogenation is continued until neither texasin nor any of the 6,7-dihydroxy-3-(4-methoxyphenyl)chromanon-4 was detected by thin layer chromatography. The further purification was identical to that described in Example 12. The product has the formula C16H16O4, molecular weight 272, and melting point 160° C. It was characterized by UV, NMR, IR and Mass spectroscopy and determined to be 6,7-dihydroxy-3-(4-methoxyphenyl)chroman. As in Example 12, the product is actually a mixture of optical isomers but since the isomers exhibit the same properties further characterization was not deemed necessary for the purposes of this disclosure. Therefore, it is to be understood that the scope of the disclosure and claims embraces the optical isomers of the compounds discussed herein.

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