反应详情

Potassium carbonate (575 mg, 4.16 mmol) and benzyl bromide (0.495 mL, 4.16 mmol) were added to a solution of cyclobutane-1,3-dicarboxylic acid (cis-trans mixture) (200 mg, 1.39 mmol) in DMF (4.0 mL) at room temperature, and the mixture was stirred overnight at room temperature. To the reaction mixture was added water at room temperature, and the mixture was extracted with ethyl acetate. The organic layer was washed with water and brine, and dried over magnesium sulfate, and the solvent was evaporated under reduced pressure. The obtained residue was purified by silica gel column chromatography (solvent gradient; 0→5% ethyl acetate/hexane) to give dibenzyl cis-cyclobutane-1,3-dicarboxylate (106.3 mg, 0.328 mmol, 23.6%) as a less polar compound, and dibenzyl trans-cyclobutane-1,3-dicarboxylate (103.1 mg, 0.318 mmol, 22.9%) as a more polar compound, respectively. NMR spectrum of dibenzyl cis-cyclobutane-1,3-dicarboxylate

1. extractionthe mixture was extracted with ethyl acetate
2. washThe organic layer was washed with water and brine
3. dry with materialdried over magnesium sulfate
4. customthe solvent was evaporated under reduced pressure
5. customThe obtained residue was purified by silica gel column chromatography (solvent gradient; 0→5% ethyl acetate/hexane)