反应详情

To a solution of cyclobutyl methyl ketone (4 g, 40.8 mmol) in MeOH (60 mL) was added sodium methoxide (3.3 g, 61.2 mmol) at rt. After a 5 min stirring, dimethyl oxalate (4.8 g, 40.8 mmol) was added. The reaction mixture was stirred for 3 h at rt and concentrated. The residue was taked up in diluted HCl and extracted with EtOAc. The organic layers were concentrated. The residue was purified by silica gel column chromatography (hexane/EtOAc, 9:1) to provide 4 g of the title compound. Rf=0.46 (hexane/EtOAc, 1:1); 1H NMR (300 MHz, CDCl3) δ ppm 1.70-2.40 (m, 6H), 3.58 (quintet, 1H), 3.85 (s, 3H), 6.54 (s, 1H), 13.8-15.0 (br. s, 1H).

1. stirringThe reaction mixture was stirred for 3 h at rt
2. concentrationconcentrated
3. extractionextracted with EtOAc
4. concentrationThe organic layers were concentrated
5. customThe residue was purified by silica gel column chromatography (hexane/EtOAc, 9:1)