反应详情

96 g (0.448 mol) of 4-(2-ethoxy-2-oxoethyl)cyclohexanecarboxylic acid (mixture of cis and trans isomers) was dissolved in CH2Cl2 (1 L). To this solution, oxalyl chloride (76 mL, 0.885 mol) was added dropwise. The reaction was stirred at room temperature for 2 hours and then concentrated. CH2Cl2 (1 L) was added to the residue and the solvent was stripped off. The process was repeated. Next, the residue was dissolved in CH2Cl2 (1 L) and Et3N (94 mL, 0.672 mol) was added. The solution was cooled to 10° C. and benzyl alcohol (56 mL, 0.537 mol) was added dropwise. The reaction was allowed to warm to room temperature and stir at room temperature for 12 hours. Next, the solvent was removed and toluene (1 L) was added. The volume of solvent was reduced to 500 mL and the solids were removed by filtration. The filtrate was concentrated and the residue was purified by flash chromatography on silica gel (0 to 20% EtOAc/heptanes) to afford benzyl trans-4-(2-ethoxy-2-oxoethyl)cyclohexanecarboxylate.

1. concentrationconcentrated
2. additionCH2Cl2 (1 L) was added to the residue
3. dissolutionNext, the residue was dissolved in CH2Cl2 (1 L)
4. temperatureThe solution was cooled to 10° C.
5. temperatureto warm to room temperature
6. stirringstir at room temperature for 12 hours
7. customNext, the solvent was removed
8. additiontoluene (1 L) was added
9. customthe solids were removed by filtration
10. concentrationThe filtrate was concentrated
11. customthe residue was purified by flash chromatography on silica gel (0 to 20% EtOAc/heptanes)