반응 #1857550

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(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

수율 77.0%

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

수율 77.0%

용매

DCM

반응 조건

후처리

1. 1
   기타The reaction mixture was removed from the cold bath
2. 2
   workup.ADDITIONHexane (50 mL) was added to the reaction
3. 3
   기타the precipitate was removed by filtration
4. 4
   세척The 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
   기타the solvent was removed under reduced pressure
7. 7
   기타purified

실험 절차

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]+).

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