反応 #1293

反応方程式

cesium carbonate

(S)-2-phthalimido-6-hydroxyhexanoic acid

benzyl bromide

→

title product

(S)-2-Phthalimido-6-hydroxyhexanoic acid, phenylmethyl ester

溶媒

dimethylformamide

反応条件

後処理

1. 1
   その他the mixture was partitioned between ethyl acetate and water
2. 2
   抽出The organic extract
3. 3
   洗浄was washed with water (twice) and brine
4. 4
   乾燥dried (sodium sulfate)
5. 5
   ろ過filtered
6. 6
   その他to give an oil
7. 7
   その他chromatographed (Merck silica gel, 6/4-ethyl acetate/hexane)
8. 8
   その他to give essentially pure product as a solid
9. 9
   その他Recrystallization from ethyl acetate/hexane
10. 10
    その他gave 7.173 g

実験手順

A slurry of cesium carbonate (3.819 g, 11.7 mmol.) and (S)-2-phthalimido-6-hydroxyhexanoic acid (6.00 g, 21.6 mmol.) in dimethylformamide (60 ml.) was treated with benzyl bromide (3.30 ml., 4.75 g., 27.7 mmol.). After stirring at room temperature for 2 hours, the mixture was partitioned between ethyl acetate and water. The organic extract was washed with water (twice) and brine, then dried (sodium sulfate), filtered and stripped to give an oil. The oil was flash chromatographed (Merck silica gel, 6/4-ethyl acetate/hexane) to give essentially pure product as a solid. Recrystallization from ethyl acetate/hexane gave 7.173 g. (1st crop) and 394 mg. (2nd crop) for a total of 7.567 g. of pure title product; m.p. 106°-108.5° C.; [α]D =-27-5° (c=1.5, methanol). TLC (75/25 ethyl acetate/hexanes) Rf =0.43.

出典