反应详情

Sodium hydroxide (1N, 22.5 mmol) was added dropwise (1 drop for every 20 seconds) to a stirred solution of diethyl 1,1-cyclobutanedicarboxylate (4.5 g, 22.5 mmol) in ethanol (20 ml). The resulting mixture was stirred at room temperature for 6 hours, then concentrated by evaporation to a volume of about 10 ml. This residue was shaked with diethyl ether and the aqueous layer was separated. This aqueous was acidified with 12N hydrochloric acid while the temperature was kept below 10° C. The resulting mixture was extracted with diethyl ether (3×50 ml). The combined extracts were dried over magnesium sulfate, filtered and evaporated to yield the desired product as a colorless oil.

1. concentrationconcentrated by evaporation to a volume of about 10 ml
2. customthe aqueous layer was separated
3. customwas kept below 10° C
4. extractionThe resulting mixture was extracted with diethyl ether (3×50 ml)
5. dry with materialThe combined extracts were dried over magnesium sulfate
6. filtrationfiltered
7. customevaporated