Roman V. Rozhkov, Richard C. Larock
FULL PAPERS
vial for 5min, and then water (1 mL) and the 1,3-diene
(1.0 mmol) were added. The resulting reaction mixture was
stirred at 1008C for 24 h, cooled to room temperature, filtered
and the filtrate was concentrated to give a yellow residue. This
residue was purified bycolumn chromatography using silica gel
as a solid phase and 4:1 hexanes/ethyl acetate as the eluent to
afford, after solvent removal, the final product. Solid products
were then recrystallized from 1:1 ethanol/water. Experimental
procedures and spectral data for all newly synthesized flavo-
noids are available in the Supporting Information.
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Acknowledgements
We gratefully acknowledge the donors of the PetroleumRe-
search Fund, administered by the American Chemical Society,
for partial support of this research and Johnson Matthey, Inc.
and Kawaken Fine Chemicals Co., Ltd. for donations of palla-
diumacetate.
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Adv. Synth. Catal. 2004, 346, 1854–1858