Condensed tannins. 14. Formation of (−)-3′, 4′, 5′, 7-tetrahydroxyflavanone and (+)-3′, 4′, 5′, 7-tetrahydroxyflavan-4-ol by interconversion from (+)-dihydrorobinetin, and synthesis of their racemates
- 1 August 1962
- journal article
- research article
- Published by Portland Press Ltd. in Biochemical Journal
- Vol. 84 (2) , 416-421
- https://doi.org/10.1042/bj0840416
Abstract
The analogues robtein, ([plus or minus])-robtin and ([plus or minus]])-3[image],4[image],5[image],7-tetrahydroxyflavan-4-ol have been synthesized. The sequence of conversions (+)-dihydro-robinetin [forward arrow] (-)-robtin[forward arrow] (+)-3[image],4[image],5[image],7-tetrahydroxyflavan-4-ol and (+)-fustin[forward arrow](-)-butin[forward arrow](+)-3[image],4[image],7-trihydroxyflavan-4-ol has been effected in each instance by means of a Clemmensen-type reduction followed by catalytic hydrogenation. These interconversions establish the absolute configurations of flavanones as (2S), and those of the flavan-4-ols tentatively as (2S, 4R). The biochemical significance of the ready conversion of flavanonol into flavanone is discussed.Keywords
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