反应详情

温度

50 °C

A solution of 3-azido-2(R)-methoxy-propanal diethyl acetal 24 (934 mg, 4.6 mmol) prepared by methylation of 3-azido-2(R)-hydroxy-propanal diethyl acetal obtained enzymatically; von der Osten, C. H.; Barbas, C. F.; Wong, C. H.; Pederson, R. L.; Sinskey, A. J.; Wang, Y. F. J. Am. Chem. Soc. 1989, 111, 3924) was dissolved in water (5 mL) and Dowex 50W-X8 (H+ form, 200-400 mesh) was added until pH <2. The mixture was heated at 50° C. for 8 hours, then the resin was filtered off and washed with a minimum amount of water. A solution of DHAP (262 mM, 7.6 mL, 2 mmol) was added and the mixture was adjusted to pH 6.5 with 6N NaOH. Fructose-1,6-diphosphate aldolase was added (1.4 mL, 500 units; see general section—supra) and the mixture was stirred at room temperature. After 4 h the pH was adjusted to 4.7 with HCl. Acid phosphatase (500 μL, 400 units—see general materials section, supra) was added and the mixture heated at 37° C. The enzyme was precipitated by adding acetone and these residue evaporated and chromatographed on SiO2 (CH2Cl2:MeOH 6:1), to give 400 mg (40%) of (35,4R,5S)-6-azido-5-methoxy-1,3,4-trihydroxyhexan-2-one 26: 1H-NMR (D2O, δ, ppm) 4.48 and 4.35 (1H each, J=19.8 Hz, H1 and H1′); 4.38 (1H, d, J=3 Hz, H3); 3.85 (1H, dd, J=9.2 Hz, 1.9 Hz, H4), 3.7 (1H, dd, J=13.6 Hz, 2.8 Hz, H6); 3.45, (1H, ddd, J=9.2 Hz, 2.8 Hz, 3.7 Hz, H5); 3.33 (3H, s, Me); 3.30 (1H, dd, 13.5 Hz, 3.7 Hz, H6′). 13C-NMR (D2O, δ, ppm): 213.22, 78.55, 74.85, 70.26, 65.98, 57.36, 48.97.

1. customobtained enzymatically
2. addition(H+ form, 200-400 mesh) was added until pH <2
3. filtrationthe resin was filtered off
4. washwashed with a minimum amount of water
5. additionAcid phosphatase (500 μL, 400 units—see general materials section, supra) was added
6. temperaturethe mixture heated at 37° C
7. customThe enzyme was precipitated
8. additionby adding acetone
9. customthese residue evaporated
10. customchromatographed on SiO2 (CH2Cl2:MeOH 6:1)