SYNTHESIS OF ALPINUM ISOFLAVONE, DERRONE AND RELATED PYRANOISOFLAVONES

Article abstract of DOI:10.1016/S0040-4020(01)86841-1

Reaction of phenacylchroman 1 with ethoxyalyl chloride in pyridine followed by hydrolysis of the resulting esters 2 and 3 and decarboxylation of the acids 4 and 5, gave dihydro-4'-O-methyl alpinum isoflavone 6 and 4'-O-methylderrone 7 respectively.Similarly 8 gave 11 which was selectively demethylated to 7.DDQ, dehydrogenation of 6, 7 and 11 gave 14, 15 and 17.Demethylation of 6 and 7 followed by dehydrogenation gave alpinum isoflavone 18 and derrone 19.