The Structure of Cryptostrobin and Strobopinin, the Flavanones from the Heartwood of Pinus strobus.
説明
Of the flavanones contained in the heartwood of Pinus strobus, cryptostrobin (m. p. 202∼203°) and strobopinin (m. p. 225∼227°), the former was synthesized and its structure was determined as 5, 7-dihydroxy-8-methylflavanone. It was thereby clarified that strobopinin, its isomer, would be its 6-methyl compound. In this synthesis, 2'-hydroxy-3'-methyl-4', 6'-dibenzyloxychalcone was prepared from 2-hydroxy-3-methyl-4, 6-dibenzyloxyacetophenone, boiled with ethanolic phosphoric acid for a long time, and 5, 7-dibenzyloxy-8-methylflavanone thereby obtained was reduced with palladium-carbon catalyst to 5, 7-dihydroxy-8-methylflavanone, m. p. 202∼203°, which was proved to be identical with cryptostrobin by a mixed fusion and by a comparison of their Rf-values. The acetate of 7-methyl ether of this flavanone afforded 5-hydroxy-7-methoxy-8-methylflavone by bromination-dehydrobromination. On the other hand, this flavone was found to be identical with partially demethylated compound of 5, 7-dimethoxy-8-methylflavone prepared from 2-hydroxy-3-methyl-4, 6-dimethoxyacetophenone by the Baker-Venkataramann method.
収録刊行物
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- Pharmaceutical Bulletin
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Pharmaceutical Bulletin 5 (3), 195-198, 1957
公益社団法人 日本薬学会