反应详情

Using the procedure of Example 12, 1.42 g of racemic-3,4-dihydro-2,5,7,8-tetramethyl-6-hydroxy-2H-1-benzopyran-2-acetic acid methyl ester was alkylated with allyl bromide (2.79 g) and sodium hydride (5.58 mmole) in anhydrous N,N-dimethylformamide. There was obtained 1.35 g (83.1%) of racemic-3,4-dihydro-2,5,7,8-tetramethyl-6-(2-propenyloxy)-2H-1-benzopyran-2-acetic acid methyl ester as a yellow oil, after column chromatographic purification (silica gel, 9:1 hexane-ethyl acetate).