반응 #2056804

반응 방정식

ethyl 2-ethyl-4-hydroxycyclopentanecarboxylate

4-methoxybenzyl 2,2,2-trichloroacetimidate

trifluoromethanesulfonic acid

→

ethyl 2-ethyl-4-(4-methoxybenzyloxy)cyclopentanecarboxylate

수율 64.0%

용매

DCM

cyclohexane

반응 조건

후처리

1. 1
   기타The ice bath was removed
2. 2
   workup.STIRRINGthe reaction mixture was stirred at ambient temperature for about 16 h
3. 3
   workup.ADDITIONThe suspension was poured into ice-water (500 mL)
4. 4
   workup.STIRRINGstirred for about 30 min
5. 5
   기타The solid was removed by filtration
6. 6
   세척while washing with DCM (100 mL)
7. 7
   기타The layers in the filtrate were separated
8. 8
   추출the aqueous layer was extracted with DCM (3×200 mL)
9. 9
   세척The combined organic layers were washed with water (200 mL)
10. 10
    건조dried over anhydrous MgSO4
11. 11
    여과filtered
12. 12
    기타The crude material was purified
13. 13
    세척eluting with a gradient of 0-100% DCM:EtOAc (95:5) in DCM

실험 절차

To a mixture of ethyl 2-ethyl-4-hydroxycyclopentanecarboxylate (37.78 g, 203 mmol, Preparation #P.1) in DCM (100 mL) and cyclohexane (200 mL) at about 0° C. was added 4-methoxybenzyl 2,2,2-trichloroacetimidate (93.58 g, 331 mmol) followed by dropwise addition of trifluoromethanesulfonic acid (1.6 mL, 18.0 mmol) over about 35 min. The reaction mixture was stirred at about 0° C. for about 30 min. The ice bath was removed and the reaction mixture was stirred at ambient temperature for about 16 h. The suspension was poured into ice-water (500 mL) and stirred for about 30 min. The solid was removed by filtration while washing with DCM (100 mL). The layers in the filtrate were separated and the aqueous layer was extracted with DCM (3×200 mL). The combined organic layers were washed with water (200 mL), dried over anhydrous MgSO4, filtered, and concd under reduced pressure. The crude material was purified using silica gel chromatography eluting with a gradient of 0-100% DCM:EtOAc (95:5) in DCM to give ethyl 2-ethyl-4-(4-methoxybenzyloxy)cyclopentanecarboxylate (39.80 g, 64%): LC/MS (Table 1, Method b) Rt=2.90 min; MS m/z: 307 (M+H)+.

출처