反应详情

A mixture of 7.16 g (20 mmol) of rac-(E)-3-[2-hydroxy-6-[6-[(tetrahydro-2H-pyran-2-yl)oxy]-1-hexynyl]phenyl]-2-propenoic acid methyl ester (preceding example), 4.37 g (22.4 mmol) of ethyl 4-bromobutyrate, 8.32 g (60.29 mmol) of anhydrous, granular potassium carbonate, and 50 mL of dry dimethyl sulfoxide was stirred at room temperature for 23 hr. The resulting mixture was diluted with ether and worked-up in the usual manner. There was obtained 9.73 g of rac-(E)-4-[2-(3-methoxy-3-oxo-1-propenyl)-3-[6-[(tetrahydro-2H-pyran-2-yl)oxy]-1-hexynyl]phenoxy]butanoic acid ethyl ester as a yellow oil containing ca. 10% of ethyl 4-bromobutyrate (NMR analysis). This material was used without further purification.