Methanol → 7-Decyl-3-hydroxy-2-(2,4,5-trihydroxyphenyl)-4H-1-benzopyran-4-one

Participants

Reaction Steps

Boron tribromide (1.0 M solution in DCM) (4.0 ml, 4.06 mmol, 5.0 eq) was added slowly to a solution of 69 (392 mg, 0.81 mmol) in dry DCM (3 ml) at 0° C. under argon. The solution was then stirred overnight and then methanol (5 ml) added slowly. The solution was heated under reflux for 30 min. then concentrated under vacuum. Water (20 ml) was added to the residue and the flask placed in a sonic bath for 5 min. The resulting fine precipitate was filtered off and washed with water (10 ml) then freeze dried to give the flavonol as a red/brown amorphous solid (338 mg, 98%). m.p. decomp >90° C.

Provenance & Evidence