반응 #8852

반응 방정식

ammonium chloride

propionaldehyde

tert-butyl 4-acetyl-4-methoxypiperidine-1-carboxylate

tert-Butyl 4-acetyl-4-methoxypiperidine-1-carboxylate

lithium diisopropylamine

→

title compound

수율 55.9%

tert-Butyl 4-(3-hydroxy-1-oxopent-1-yl)-4-methoxypiperidine-1-carboxylate

수율 55.9%

용매

tetrahydrofuran

반응 조건

후처리

1. 1
   추출extracted three times with diethyl ether
2. 2
   세척washed with saturated sodium chloride solution
3. 3
   건조dried over sodium sulfite
4. 4
   여과filtered
5. 5
   농축concentrated
6. 6
   기타The residue was purified by flash chromatography
7. 7
   세척eluting with 40% ethyl acetate/hexanes

실험 절차

To a solution of tert-butyl 4-acetyl-4-methoxypiperidine-1-carboxylate (0.589 g, 2.29 mmol) from Step A in tetrahydrofuran (20 mL) at −78° C. was added lithium diisopropylamine (0.650 mL, 0.974 mmol) followed by propionaldehyde (0.266 g, 0.330 mL, 4.58 mmol). After 5 min, the reaction mixture was poured into saturated ammonium chloride, and extracted three times with diethyl ether. The organic layers were combined, washed with saturated sodium chloride solution, dried over sodium sulfite, filtered, and concentrated. The residue was purified by flash chromatography eluting with 40% ethyl acetate/hexanes to afford the title compound (0.404 g). MS/EI (acetonitrile/water): m/z 216.1 (M+1−BOC) retention time=2.69 min.

출처