A solution of 8-isopropyl-2,2,4,4-tetramethyl-chroman-6-carboxylic acid (Intermediate 34, 0.05 g, 0.18 mmol) and 3-(4-hydroxy-phenyl)-acrylic acid benzyl ester (described in Journal of Natural Products, 1990, 53 (4), p 821–824, Bankova V., 0.046 g, 0.18 mmol) in anhydrous dichloromethane (5 mL) was treated with 4-(dimethylamino)pyridine (0.052 g, 0.27 mmol) and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (0.044 g, 0.36 mmol) and the resulting reaction mixture was stirred at ambient temperature overnight. The reaction mixture was then subjected to flash column chromatography using 20% ethyl acetate in hexane as the eluent to afford the title compound as a white solid (0.076 g, 83%).
