反应详情

To a solution of ethyl 2-ethoxycarbonyl-3,3-dimethylhexanoate (24.5 g, 100 mmol) in ethanol (150 ml), was added aqueous sodium hydroxide solution (1N, 180 ml, 180 mmol) and the mixture was stirred at room temperature for 24 hours and then at 40° C. for additional 2 hours. Aqueous hydrogen chloride (3N, 60 ml, 180 mmol) was added to the reaction mixture and the resulting mixture was then concentrated to 150 ml. The mixture was extracted with ethyl acetate (200 ml) and the aqueous layer was further extracted with ethyl acetate (50 ml×2). The combined organic layers were washed with water (100 ml) and with brine (100 ml), and dried over anhydrous magnesium sulfate. The resulting solution was concentrated and the residue was stirred at 180° C. for 2.5 hours. Ether (30 ml) was added to the reaction mixture. The resulting mixture was then treated with diazomethane. After removing off ether, the residue was further distilled under reduced pressure to give oily product, ethyl 3,3-dimethylhexanoate (11.07 g, 64.4 mmol), 64.4%, b.p.: 87°-94° C./22 mmHg). The structure was identified by the following data.

1. waitat 40° C. for additional 2 hours
2. concentrationthe resulting mixture was then concentrated to 150 ml
3. extractionThe mixture was extracted with ethyl acetate (200 ml)
4. extractionthe aqueous layer was further extracted with ethyl acetate (50 ml×2)
5. washThe combined organic layers were washed with water (100 ml) and with brine (100 ml)
6. dry with materialdried over anhydrous magnesium sulfate
7. concentrationThe resulting solution was concentrated
8. stirringthe residue was stirred at 180° C. for 2.5 hours
9. additionEther (30 ml) was added to the reaction mixture
10. additionThe resulting mixture was then treated with diazomethane
11. customAfter removing off ether
12. distillationthe residue was further distilled under reduced pressure