反応 #1049544

反応方程式

ethyl acetate

Racemic 1-O-octadecyl-2-O-benzyl-3-bromo-1,2-propanediol

tetrahydrofuran

sodium thiomethoxide

→

1-O-octadecyl-2-O-benzyl-3-methylthio-1,2-propanediol

収率 90.0%

溶媒

chloroform

hexane

反応条件

後処理

1. 1
   その他equipped with a magnetic stir bar
2. 2
   ろ過The mixture was filtered
3. 3
   洗浄the filtrate was washed with 50 ml tetrahydrofuran
4. 4
   濃縮The combined filtrates were concentrated under vacuum
5. 5
   その他a rotary evaporator
6. 6
   その他to afford a yellow residue
7. 7
   洗浄the organic solution washed twice with 30 ml of a concentrated solution of sodium bicarbonate
8. 8
   乾燥The organic phase was then dried over anhydrous magnesium sulfate
9. 9
   濃縮concentrated on a rotary evaporator under vacuum
10. 10
    その他to afford the crude product as a pale yellow oily residue
11. 11
    その他This crude product was purified by chromatography on silica gel 60 (E. Merck, Germany)
12. 12
    その他The fractions collected
13. 13
    workup.ADDITIONThose fractions containing pure product (silica gel, 5% ethyl acetate in hexane, Rf=0.51)
14. 14
    濃縮concentrated

実験手順

Racemic 1-O-octadecyl-2-O-benzyl-3-bromo-1,2-propanediol, 1.99 g (4.0 mmoles), was dissolved into 100 ml of dry tetrahydrofuran in a 250 ml round bottom flask equipped with a magnetic stir bar. To this solution was added 2.8 g (40.0 mmoles) of sodium thiomethoxide powder and the reaction mixture stirred for 4.5 hours at room temperature. The reaction was monitored by TLC (silica gel, 5% ethyl acetate in hexane; Rf=0.51). The mixture was filtered and the filtrate was washed with 50 ml tetrahydrofuran. The combined filtrates were concentrated under vacuum using a rotary evaporator to afford a yellow residue. This residue was dissolved into 50 ml chloroform and the organic solution washed twice with 30 ml of a concentrated solution of sodium bicarbonate. The organic phase was then dried over anhydrous magnesium sulfate and concentrated on a rotary evaporator under vacuum to afford the crude product as a pale yellow oily residue. This crude product was purified by chromatography on silica gel 60 (E. Merck, Germany) using a step gradient of 0 to 10% ethyl acetate in hexane. The fractions collected were screened by TLC. Those fractions containing pure product (silica gel, 5% ethyl acetate in hexane, Rf=0.51) were pooled and concentrated to afford 1-O-octadecyl-2-O-benzyl-3-methylthio-1,2-propanediol in 90% yield.

出典