反应详情

A solution of spiro[2H-1-benzopyran-2,1′-cyclopropane]-6-carboxylic acid, 8-cyclopropyl-3,4-dihydro-4,4-dimethyl- (Intermediate 49, 0.06 g, 0.22 mmol) in anhydrous dichloromethane (5 mL) was treated with tert-butyl-4-hydroxy phenyl acetate (Reagent E, 0.05 g, 0.22 mmol) followed by 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (0.11 g, 0.22 mmol) and 4-dimethylaminopyridine (0.028 g, 0.22 mmol). The resulting solution was stirred at ambient temperature overnight. The reaction mixture was subjected to flash column chromatography over silica gel (230-400 mesh) using 7% ethyl acetate in hexane as the eluent to afford the title compound as a clear oil that solidified on standing (0.048 g, 48%).