Sodium Hydroxide → (E)-3-{4-[8-Cyclopropyl-3,4-dimethylspiro[2H-1-benzopyran-2, 1'-cyclopropane]-6-yl]ethynyl-phenyl}-2-methyl-acrylic acid

Participants

Reaction Conditions

Reaction Steps

A solution of (E)-3-{4-[8-cyclopropyl-3,4-dimethylspiro[2H-1-benzopyran-2,1′-cyclopropane]-6-yl]ethynyl-phenyl}-2-methyl-acrylic acid ethyl ester (Intermediate 3, 0.06 g, 0.13 mmol) in ethanol (2 mL) was treated with a 1M solution of sodium hydroxide (0.5 mL, 0.5 mmol) and the resulting reaction mixture was heated at 55° C. for 4 h. The reaction mixture was cooled to ambient temperature and the volatiles were evaporated in vacuo to a residue that was neutralized with 5% hydrochloric acid and extracted with ethyl acetate. The organic phase was washed with water and brine, dried over anhydrous magnesium sulfate; filtered and evaporated in vacuo to afford the title product as a yellow solid after flash column chromatography over silica gel (230–400 mesh) (0.044 g, 82%).

Provenance & Evidence