Reaktion #4520

Reaktionsgleichung

Trifluoroacetic acid

Boc-L-Ala-D-Glu-(OH)OBzl

palmitoyl-L-Ala-D-Glu(OH)OBzl

→

palmitoyl-L-Ala-D-Glu(OH)OBzl

palmitoyl-L-Ala-D-Glu(OSu)OBzl

Reaktionsbedingungen

Aufarbeitung

1. 1
   Einengenconcentrated in vacuo
2. 2
   Waschenwashed with diisopropylether
3. 3
   workup.DISSOLUTIONThe oil was dissolved in a mixture of water (15 ml) and sodium bicarbonate
4. 4
   workup.ADDITIONwas added until the pH of the solution
5. 5
   workup.ADDITIONThe mixture of water (6 ml) and acetone (20 ml)
6. 6
   workup.ADDITIONwas added to the solution and palmitoyl chloride (2.20 g)
7. 7
   workup.ADDITIONwas added in one portion
8. 8
   workup.STIRRINGAfter stirring for 30 minutes at room temperature
9. 9
   Einengenthe reaction mixture was concentrated
10. 10
    workup.ADDITIONTo the residue was added water (30 ml)
11. 11
    Sonstigethe precipitates was collected
12. 12
    Sonstigedried
13. 13
    Sonstigeto give a crude product, which
14. 14
    Sonstigewas purified by column chromatography of Silicagel (90 g) with chloroform-methanol (30:1

Vorschrift

Trifluoroacetic acid (15 ml) was added to Boc-L-Ala-D-Glu-(OH)OBzl (1)(3.26 g) and the mixture was stirred for 20 minutes at room temperature, concentrated in vacuo and washed with diisopropylether. The oil was dissolved in a mixture of water (15 ml) and sodium bicarbonate was added until the pH of the solution became 8-9. The mixture of water (6 ml) and acetone (20 ml) was added to the solution and palmitoyl chloride (2.20 g) was added in one portion. After stirring for 30 minutes at room temperature, the pH of the solution was adjusted to 3 with 1N-hydrochloric acid and the reaction mixture was concentrated. To the residue was added water (30 ml) and the precipitates was collected and dried to give a crude product, which was purified by column chromatography of Silicagel (90 g) with chloroform-methanol (30:1, v/v) as an eluent to give palmitoyl-L-Ala-D-Glu(OH)OBzl (2)(2.00 g). mp. 131°-132° C.

Quelle