反应 #54611

反应方程式

ether

H-Asp(OBzl)-Thr(Bzl)-Ser(Bzl)-Ser(Bzl)-Glu(OBzl)-OH

Boc-Val-OSu

HCl

→

Boc-Val-Asp(OBzl)-Thr(Bzl)-Ser(Bzl)-Ser(Bzl)-Glu(OBzl)-OH

溶剂

DMF

THF

THF

Et3N

Et3N

反应条件

后处理

1. 1
   其他a white solid powder was obtained (44.0 g, mp 179°-184°)
2. 2
   温度cooled to 0°
3. 3
   workup.ADDITIONwas added in several portions
4. 4
   温度maintaining
5. 5
   其他the reaction slightly basic
6. 6
   其他The insoluble matter was removed by filtration
7. 7
   其他the filtrate evaporated to dryness
8. 8
   workup.DISSOLUTIONThe oily residue was dissolved in CH2Cl2
9. 9
   洗涤washed with 5% HOAc, H2O
10. 10
    干燥dried (Na2SO4)
11. 11
    其他evaporated to a smaller volume (0.5 liter) when
12. 12
    workup.ADDITIONtreated with petroleum ether
13. 13
    其他The product crystallized slowly during overnight
14. 14
    其他It was recrystallized from THF and i-PrOH
15. 15
    其他to yield

实验过程

Boc-Asp(OBzl)-Thr(Bzl)-Ser(Bzl)-Ser(Bzl)-Glu(OBzl)-OH (50.0 g, 46 mmol) was deprotected with HCl (4.15 N) in THF and worked up as usual to give 45.4 g of white solid. It was dissolved in THF (1.5 liters) and treated with ether (7 liters). On standing at 0° overnight a white solid powder was obtained (44.0 g, mp 179°-184°). Part of this material, HCl.H-Asp(OBzl)-Thr(Bzl)-Ser(Bzl)-Ser(Bzl)-Glu(OBzl)-OH (43.7 g, 42.7 mmol) was then dissolved in 500 ml of DMF, cooled to 0°, and treated with Boc-Val-OSu (15.4 g, 49 mmol) and Et3N (10 ml). The mixture was stirred for 15 hours during which time more Et3N (7.9 ml) was added in several portions maintaining the reaction slightly basic. The insoluble matter was removed by filtration and the filtrate evaporated to dryness. The oily residue was dissolved in CH2Cl2, washed with 5% HOAc, H2O, dried (Na2SO4), and evaporated to a smaller volume (0.5 liter) when treated with petroleum ether. The product crystallized slowly during overnight standing. It was recrystallized from THF and i-PrOH to yield, 26.3 g (51.4%); mp 174°-177°; α]D25 =+0.84° (c, 1, THF).

来源