Allyl bromide → HCID 58774160, compound

Participants

Reaction Steps

To a mixture of (−)-epicatechin (1.16 g, 4 0 mmol) and potassium carbonate (1.10 g, 8.0 mmol) in dry acetone was added allyl bromide (0.41 mL, 4.8 mmol). The reaction was heated at reflux, under nitrogen, protected from light with vigorous stirring for 4 h. The reaction was filtered and concentrated onto silica gel. The crude product was purified on a Biotage 50 g silica gel column eluting with a gradient of 40-70% ethyl acetate/hexane and then 70% ethyl acetate/hexane. The major peak, corresponding to a mixture of monoallylated products, was isolated. This mixture was further purified by preparative reverse phase HPLC using a gradient of 1:9 to 8:2 acetonitrile/(0.2% formic acid/water) over 20 min. The appropriate fractions were frozen and lyophilized to give as white powders to provide 2-(4-Allyloxy-3-hydroxy-phenyl)-chroman-3,5,7-triol and 2-(3-Allyloxy-4-hydroxy-phenyl)-chroman-3,5,7-triol.

Provenance & Evidence