Reacción #1049544

Ecuación de reacción

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

Rendimiento 90.0%

Disolventes

chloroform

hexane

Condiciones de reacción

Tratamiento posterior

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

Procedimiento

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.

Fuente