反应详情

温度

100 °C

20 g of 2-ethoxycarbonyl-cyclopentanone was dissolved in 15 ml dimethylformamide and stirred. Then, a solution comprising 200 ml dimethylformamide with 6 g sodium hydride dispersed therein was gradually added dropwise to the above 2-ethoxycarbonyl-cyclopentanone solution. After the addition of the sodium hydride solution had been completed, the reaction solution was stirred for 2 hours at room temperature under a nitrogen gas stream. A solution comprising 15 ml dimethylformamide with 25 g octyl bromide dissolved therein was further added dropwise to the reaction solution. After the addition had been completed, the temperature was raised to 100° C. and agitation was conducted for 2 hours. The reaction solution was cooled down, then poured into iced water and extraction with 100 ml diethylether was conducted twice. The diethylether layer was dried with anhydrous sodium sulfate, and then the diethylether was removed to provide a crude reaction product of 2-ethoxycarbonyl-2-octyl-cyclopentanone. This crude reaction product was dissolved in 20 ml of tetrahydrofuran. A solution comprising 80 ml tetrahydrofuran with 2 g lithium borohydride dispersed therein was added dropwise to the above 2-ethoxycarbonyl-2-octyl-cyclopentanone solution under an iced condition while stirring and the stirring was further continued for 4 hours. After adding 50 ml ethylacetate and 100 ml distilled water, the solution was acidified by the addition of a 10% sulfuric acid aqueous solution to give a pH of 2. The reaction solution was extracted twice with 50 ml of diethylether. The diethylether layer was dried with anhydrous sodium sulfate, and then the diethylether was removed to provide a crude reaction product of 2-hydroxymethyl-2-octyl-cyclopentanone. This crude reaction product was purified by means of silica gel column chromatography (eluent: chloroform/methanol=97/3) and 18.9 g of 2-hydroxymethyl-2-octyl-cyclopentanol was obtained as a pale yellow, oily substance (yield: 64.7%). In the measurement of the infrared absorption spectrum, a strong absorption by a hydroxyl group at 3,370 cm-1 and, in the mass spectrometric measurement, a peak corresponding to the loss of water from the parent ion peak, were observed. Besides, in the elemental analysis, measured values of C=73.37% and H=12.45% were found (theoretical values of C and H: C=73.13% and H=12.35%). Thus, the production of 2-hydroxymethyl-2-octyl-cyclopentanol was ascertained.

1. additiondispersed
2. stirringthe reaction solution was stirred for 2 hours at room temperature under a nitrogen gas stream
3. dissolutiondissolved
4. additiontherein was further added dropwise to the reaction solution
5. additionAfter the addition
6. temperatureThe reaction solution was cooled down
7. dry with materialThe diethylether layer was dried with anhydrous sodium sulfate
8. customthe diethylether was removed
9. customto provide a crude
10. customThis crude reaction product
11. additiondispersed
12. stirringwhile stirring
13. waitthe stirring was further continued for 4 hours
14. distillationdistilled water
15. additionthe solution was acidified by the addition of a 10% sulfuric acid aqueous solution
16. customto give a pH of 2
17. extractionThe reaction solution was extracted twice with 50 ml of diethylether
18. dry with materialThe diethylether layer was dried with anhydrous sodium sulfate
19. customthe diethylether was removed
20. customto provide a crude
21. customThis crude reaction product
22. customwas purified by means of silica gel column chromatography (eluent: chloroform/methanol=97/3)