反应详情

Dimethyl sulfoxide (DMSO) (3.3 ml, 58.5 mmol) was added dropwise at -78° C. to a solution of oxazolyl dichloride (3.6 ml, 46.8 mmol) in methylene chloride and the mixture was stirred for 15 minutes. To the resulting mixture, a solution of 2-cyclohexylethanol (5.5 ml, 39.0 mmol) in methylene chloride was added dropwise and the mixture was stirred at -78° C. for 1 hour. The reaction was stopped by adding triethylamine (20 ml) and water (100 ml). The reaction mixture was extracted 3 times with diethyl ether. The organic layer was washed 3 times each with saturated aqueous solutions of ammonium chloride and NaCl and dried over anhydrous sodium sulfate. After the solvent was distilled off, the obtained oil was applied to a silica gel column (2.5×40 cm) and eluted with a mixed solution (chloroform:methanol=10:1). The desired fractions were collected and the solvents were distilled off to yield cyclohexylacetaldehyde (2.88 g, 58.4%) as an oil. The same procedure as in Example 2-(2) was performed with ethyl isobutyrate (2.14 ml, 17.8 mmol) and the obtained cyclohexylacetaldehyde (2.25 g, 17.8 mmol) to yield a crystal of 4-cyclohexylmethyl-3,3-dimethyl-2-azetidinone (0.46 g, 13.3%).

1. stirringthe mixture was stirred at -78° C. for 1 hour
2. extractionThe reaction mixture was extracted 3 times with diethyl ether
3. washThe organic layer was washed 3 times each with saturated aqueous solutions of ammonium chloride and NaCl
4. dry with materialdried over anhydrous sodium sulfate
5. distillationAfter the solvent was distilled off
6. washeluted with a mixed solution (chloroform:methanol=10:1)
7. customThe desired fractions were collected
8. distillationthe solvents were distilled off