An effective synthesis of isoorientin: the regioselective synthesis of a 6-C-glucosylflavone.
Isoorientin, a 6-C-beta-D-glucopyranosyl-3',4',5,7-tetrahydroxyflavone, was synthesized in a 15% overall yield, in ten steps, starting from the commercially available phloroacetophenone. The C-glucosyl phloroacetophenone derivative, a synthetic intermediate that contains a free hydroxyl group that is para to the glucosyl moiety, was obtained by hydrogenolysis by taking advantage of differences in the hydrogenolysis rates between a benzyl protecting group and a 2-methylbenzyl protecting group. Aldol condensation of the C-glucosyl phloroacetophenone derivative with 3,4-bis-benzyloxybenzaldehyde afforded the corresponding chalcone as a precursor of the 6-C-glucosyl flavone. Construction of the flavone system by application of I2-DMSO, followed by deprotection, yielded isoorientin.
Kumazawa
T
T
Department of Materials Science and Engineering, Faculty of Engineering, Yamagata University, Japan. tk111@dip.yz.yamagata-u.ac.jp
Minatogawa
T
T
Matsuba
S
S
Sato
S
S
Onodera
J
J
D005419:Flavonoids / Q000138:chemical synthesis* / Q000737:chemistry; D007202:Indicators and Reagents; D047311:Luteolin; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D010084:Oxidation-Reduction; D016339:Spectrometry, Mass, Fast Atom Bombardment
D005419:Flavonoids; D007202:Indicators and Reagents; C057912:homoorientin; D047311:Luteolin