反応 #575281

反応方程式

hydrochloric acid

N,N-diphenylacetamide

lithium diisopropylamide

(R)-4-cyano-3-hydroxybutyric acid, ethyl ester

→

N,N-diphenylhexanamide

溶媒

tetrahydrofuran

tetrahydrofuran heptane

tetrahydrofuran

反応条件

後処理

1. 1
   温度while maintaining the temperature between -10° C. to -5° C
2. 2
   workup.STIRRINGThe reaction mixture is stirred for 30 minutes at -5° C. to -20° C.
3. 3
   抽出The aqueous layer is extracted with 500 mL of ethyl acetate
4. 4
   その他the aqueous layer is separated
5. 5
   濃縮concentrated in vacuo
6. 6
   その他to afford crude (R)-6 -cyano-5-hydroxy-3-oxo

実験手順

To a stirred -10° C. solution of N,N-diphenylacetamide (211 g, 1.0 mol) in tetrahydrofuran (1.0 L) is slowly added a solution of lithium diisopropylamide in tetrahydrofuran-heptane (0.5 L of 2M) while maintaining the temperature between -10° C. to -5° C. The mixture is stirred at -0° C. to 20° C. for 30 minutes. (R)-4-cyano-3-hydroxybutyric acid, ethyl ester (Brower, supra) (40 g, 0.25 mol) as a solution in 200 mL of tetrahydrofuran is added to the previously prepared anion. The reaction mixture is stirred for 30 minutes at -5° C. to -20° C., and transferred to a 2.2N aqueous hydrochloric acid solution (1 L). The aqueous layer is extracted with 500 mL of ethyl acetate, the aqueous layer is separated and reextracted with 100 mL of ethyl acetate, the extracts are combined and concentrated in vacuo to afford crude (R)-6 -cyano-5-hydroxy-3-oxo. N,N-diphenylhexanamide which is not isolated. A small sample is purified by column chromatography on flash silica gel (60:40 hexane:ethyl acetate) as an oil. Proton nuclear magnetic resonance spectroscopy (1H-NMR): (Acetone-d6) δ2.02 (m, 2H), 2.73 (m, 2H), 4.1 (m, 2H), 4.52 (m, 1H), 4.74 (s, 1H), 7.2-7.4 (m, 10H).

出典