反应详情

A solution of 3-benzyloxy-1-propyne (1 molar equivalent) in dry ether is added dropwise to a stirred solution of ethylmagnesium bromide (1 molar equivalent) in ether at ambient temperature under a nitrogen atmosphere. Upon completing the addition, the reaction mixture is stirred at ambient temperature until gas evolution (ethane generation) ceases, then is cooled to 0° to 5° C. and treated with cyclohexanone (1 molar equivalent) added dropwise at such a rate as to prevent the reaction mixture from attaining room temperature. After completing the addition, the reaction mixture is allowed to warm to room temperature, then is heated at reflux for 1 hour. In vacuo evaporation of the reaction mixture at 40° C. provides a gelatinous residue which is treated with anhydrous tetrahydrofuran and acetic anhydride (1 molar equivalent) and then heated at reflux under a nitrogen atmosphere for 1/2 hour. After cooling to 0° to 5° C., the reaction mixture is slowly diluted with cold 2 N hydrochloric acid, stirred at 0° to 5° C. for 15 minutes and allowed to warm to room temperature. The resulting turbid reaction mixture is extracted several times with ether. The combined organic extract is washed with water (until washings are neutral to Litmus paper) and saturated aqueous brine, dried over sodium sulfate, and filtered. Evaporation (in vacuo at 40° C.) of the filtrate provides the title compound as an essentially colorless oil.

1. additionthe addition
2. temperatureis cooled to 0° to 5° C.
3. additionadded dropwise at such a rate as
4. customfrom attaining room temperature
5. additionthe addition
6. temperatureis heated
7. temperatureat reflux for 1 hour
8. customIn vacuo evaporation of the reaction mixture at 40° C.
9. customprovides a gelatinous residue which
10. temperatureheated
11. temperatureat reflux under a nitrogen atmosphere for 1/2 hour
12. temperatureAfter cooling to 0° to 5° C.
13. temperatureto warm to room temperature
14. customThe resulting turbid reaction mixture
15. extractionis extracted several times with ether
16. extractionThe combined organic extract
17. washis washed with water (until washings are neutral to Litmus paper) and saturated aqueous brine
18. dry with materialdried over sodium sulfate
19. filtrationfiltered
20. customEvaporation (in vacuo at 40° C.) of the filtrate