SYNTHESIS OF 4',5- AND 3',4',5-OXYGENATED PYRANOISOFLAVONES: ALPINUM ISOFLAVONE AND RELATED COMPOUNDS, AND REVISED STRUCTURE OF DERRONE

Article abstract of DOI:10.3987/COM-91-5918

Alpinumisoflavone (4',5-dihydroxy-2",2"-dimethylpyrano<5",6"-g>isoflavone) (1a) was synthesized by regioselective reduction of 7-(4-hydroxyphenyl)-2,3-dihydro-5-methoxy-2,2-dimethyl-4H,6H-benzo<1,2-b:5,4-b'>dipyran-4,6-dione (15a) with NaBH4 and dehydrati