反応 #8852

反応方程式

ammonium chloride

propionaldehyde

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

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

lithium diisopropylamine

→

title compound

収率 55.9%

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

収率 55.9%

溶媒

tetrahydrofuran

反応条件

後処理

1. 1
   抽出extracted three times with diethyl ether
2. 2
   洗浄washed with saturated sodium chloride solution
3. 3
   乾燥dried over sodium sulfite
4. 4
   ろ過filtered
5. 5
   濃縮concentrated
6. 6
   その他The residue was purified by flash chromatography
7. 7
   洗浄eluting with 40% ethyl acetate/hexanes

実験手順

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.

出典