反応 #1857550

反応方程式

(S)-methyl 2-((S)-1-hydroxyethyl)-5-methylhexanoate

((1S,4R)-7,7-dimethyl-2-oxobicyclo[2.2.1]heptan-1-yl)methanesulfonic acid

4-methoxybenzyl 2,2,2-trichloroacetimidate

→

title compound

収率 77.0%

(S)-methyl 2-((S)-1-((4-methoxybenzyl)oxy)ethyl)-5-methylhexanoate

収率 77.0%

溶媒

DCM

反応条件

後処理

1. 1
   その他The reaction mixture was removed from the cold bath
2. 2
   workup.ADDITIONHexane (50 mL) was added to the reaction
3. 3
   その他the precipitate was removed by filtration
4. 4
   洗浄The solids were washed with hexanes (2×10 mL), Celite® (2 scoopula tip-fulls)
5. 5
   workup.ADDITIONwas added to the combined filtrate and washes
6. 6
   その他the solvent was removed under reduced pressure
7. 7
   その他purified

実験手順

To a solution of (S)-methyl 2-((S)-1-hydroxyethyl)-5-methylhexanoate (5.00 g, 26.6 mmol) and ((1S,4R)-7,7-dimethyl-2-oxobicyclo[2.2.1]heptan-1-yl)methanesulfonic acid (camphorsulfonic acid, CSA; 0.617 g, 2.66 mmol) in DCM (53.1 mL) was added 4-methoxybenzyl 2,2,2-trichloroacetimidate (8.27 mL, 39.8 mmol) at 0° C. The reaction mixture was removed from the cold bath and stirred at room temperature for 17 h. Hexane (50 mL) was added to the reaction and the precipitate was removed by filtration. The solids were washed with hexanes (2×10 mL), Celite® (2 scoopula tip-fulls) was added to the combined filtrate and washes, and the solvent was removed under reduced pressure. The resulting adsorbed material was directly loaded onto a column and purified using flash column chromatography (80 g SiO2, 0→35% EtOAc/hexanes) to afford the title compound (6.3 g, 20.4 mmol, 77%) as a colorless oil; 1H NMR (400 MHz, CDCl3) δ 7.24-7.16 (m, 2H), 6.89-6.79 (m, 2H), 4.49 (d, J=11.2 Hz, 1H), 4.33 (d, J=11.1 Hz, 1H), 3.75 (s, 3H), 3.74-3.62 (m, 4H), 2.49 (ddd, J=10.7, 8.2, 4.0 Hz, 1H), 1.62-1.40 (m, 3H), 1.23-1.16 (m, 3H), 1.16-1.03 (m, 2H), 0.87 (d, J=3.9 Hz, 3H), 0.85 (d, J=3.9 Hz, 3H); 13C NMR (101 MHz, CDCl3) δ 175.03, 159.10, 130.63, 129.14, 113.62, 76.16, 70.71, 55.11, 52.64, 51.25, 36.58, 27.97, 26.00, 22.69, 22.17, 17.08; ESIMS m/z 331 ([M+Na]+).

出典