Phenol → Chroman

Participants

Reaction Steps

To a solution of phenol 4 (0.01 mol) and a catalyst, preferably boron trifluoride diethyl etherate (0.016 mol) in an organic solvent, preferably dry dioxane (10 mL), is added vinyl lactone 2 (0.016 mol) in an organic solvent, preferably dry dioxane (5.0 mL) over 1-60 minutes, preferably 60 minutes at 0-150° C., preferably 110° C., under an inert gas. The reaction mixture is stirred for 0 to 8 hours, preferably 0 hours, at the selected temperature, cooled to room temperature, and diluted with an organic solvent, preferably diethyl ether (200 mL). The reaction mixture is then washed with water (100 mL, 2×50 mL), dried over sodium sulfate (Na2SO4), and solvent is removed under reduced pressure to afford a brown oily residue. The residue is dissolved in alcohol, preferably methanol (30 mL), and the alcohol is then removed under reduced pressure. The brown oily liquid or semisolid is further purified by chromatography, preferably on silica gel, to afford pure racemic chroman derivative 5.

Provenance & Evidence