反応 #2012856

反応方程式

water

ethyl (2E,4E,8Z,11Z,14Z,17Z)-2-methyl-icosa-2,4,8,11,14,17-hexaenoate

Ethyl (2E,4E,8Z,11Z,14Z,17Z)-2-methyl-icosa-2,4,8,11,14,17-hexaenoate

KOH

→

acid 11

(2E,4E,8Z,11Z,14Z,17Z)-2-methyl-icosa-2,4,8,11,14,17-hexaenoic acid

溶媒

methanol

反応条件

後処理

1. 1
   温度The solution was cooled
2. 2
   抽出The mixture was then extracted with ethyl acetate
3. 3
   洗浄The combined organic phases were washed with water
4. 4
   乾燥dried (MgSO4)
5. 5
   その他Evaporation of the solvents under reduced pressure

実験手順

To a solution of ethyl (2E,4E,8Z,11Z,14Z,17Z)-2-methyl-icosa-2,4,8,11,14,17-hexaenoate (10) in methanol was added an aqueous solution of KOH (8 equiv.) and the mixture was heated to 60-70° C. for 2 hrs. The solution was cooled, water was added and the mixture acidified. The mixture was then extracted with ethyl acetate. The combined organic phases were washed with water and dried (MgSO4). Evaporation of the solvents under reduced pressure followed by flash chromatography on silica gel (8:2 hexane-EtOAc) gave the acid 11. δH(300 MHz): 0.96 (t, J 7.5, 3H, CH3), 1.91 (d, J 0.75, 3H, CH3), 2.08 (m, 2H), 2.2-2.4 (m, 4H), 2.7-2.9 (m, 6H), 5.2-5.5 (m, 8H), 6.11 (dt, J 15.0, J 6.5, 1H), 6.37 (dd, J 15.0, J 11.3, 1H), 7.26 (br d, J 11.3, 1H); δc(75 MHz) 12.16, 14.24, 20.53, 25.52, 25.61, 25.67, 26.57, 33.24, 124.44, 126.34, 126.97, 127.82, 128.04, 128.21, 128.54, 128.70, 128.74, 132.01, 140.79, 143.47, 174.28.

出典