Abstract
The potentially important dietary antioxidant, quercetin 3-
O-β-
d-glucoside, has been
13C-labelled at C-2 of the flavonoid unit by synthesis in 15% yield over five steps from [
13C]carbon dioxide. The route is appropriate for radiochemical synthesis. Formation of the protected 3-glucosylated flavonol appears to result from [1,7]-sigmatropic rearrangement with migration of a benzyl group followed by cyclisation. A free 5-OH results even when a phosphazene superbase is used.
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