反应详情

The aldehyde Z-Ala-Ala-Asn(Trt)-H (4) was prepared according to the method of Fehrentz and Castro, 2000: To a stirred solution of Z-Ala-Ala-Asn(Trt)-N(OCH3)CH3 (1.50 g, 2.16 mmol) in absolute THF (20 ml) was added dropwise lithium aluminium hydride (1.0 M, 2.7 ml, 2.7 mmol) at 0° C. After 15 minutes the mixture was hydrolyzed with aqueous citric acid (10 ml) and after brought to room temperature the solvent was evaporated in vacuo. The mixture was diluted with pH-7 buffer solution (15 ml). The organic material was extracted (5×30 ml) with ethyl acetate. The organic layer was dried over Na2SO4, filtered and concentrated under reduced pressure to give the aldehyde as a white solid (1.25 g, 91%), which was used without further purification.—TLC (MeOH/CHCl3, 1:9): Rf=0.64.—1H NMR (400 MHz, CDCl3): δ=1.33 (d, 3 H, J=7.0 Hz, CH3), 1.37 (d, 3 H, J=7.2 Hz, CH3), 2.56-2.72 (m, 2 H, CHCH2), 4.08-4.13 (m, 1 H, CH), 4.28-4.34 (m, 1 H, CH), 4.54-4.63 (m, 1 H, CH), 5.04-5.09 (m, 2 H, CH2O), 7.24-7.32 (m, 20 H, aryl-H), 9.49 (s, 1 H, aldehyde).—MS (EI) m/z (%): 635 [M+H+], 657 [M+Na+], 732 [M+K+].

1. customThe aldehyde Z-Ala-Ala-Asn(Trt)-H (4) was prepared
2. customafter brought to room temperature
3. customwas evaporated in vacuo
4. additionThe mixture was diluted with pH-7 buffer solution (15 ml)
5. extractionThe organic material was extracted (5×30 ml) with ethyl acetate
6. dry with materialThe organic layer was dried over Na2SO4
7. filtrationfiltered
8. concentrationconcentrated under reduced pressure