Reaktion #162023

ord-8dbce2d80a6f4389b7acbbf9c88a9b4c

Reaktionsgleichung

O=C(OC[C@H]1O[C@H](O[C@@H]2[C@H](OC(=O)c3ccccc3)[C@@H](O[C@H]3[C@H](OC(=O)c4ccccc4)[C@@H](COC(=O)c4ccccc4)OC(O)[C@H]3OC(=O)c3ccccc3)O[C@H](COC(=O)c3ccccc3)[C@H]2OC(=O)c2ccccc2)[C@@H](OC(=O)c2ccccc2)[C@@H](OC(=O)c2ccccc2)[C@@H]1OC(=O)c1ccccc1)c1ccccc1
hemiacetal
O=C(OC[C@H]1O[C@H](O[C@@H]2[C@H](OC(=O)c3ccccc3)[C@@H](O[C@H]3[C@H](OC(=O)c4ccccc4)[C@@H](COC(=O)c4ccccc4)OC(O)[C@H]3OC(=O)c3ccccc3)O[C@H](COC(=O)c3ccccc3)[C@H]2OC(=O)c2ccccc2)[C@@H](OC(=O)c2ccccc2)[C@@H](OC(=O)c2ccccc2)[C@@H]1OC(=O)c1ccccc1)c1ccccc1
2,3,4,6-tetra-O-benzoyl-α-D-mannopyranosyl-(1→3)-2,4,6-tri-O-benzoyl-α-D-mannopyranosyl-(1→3)-2,4,6-tri-O-benzoyl-D-mannopyranose
N#CC(Cl)(Cl)Cl
trichloroacetonitrile
CCCCCC.CCOC(C)=O
hexane EtOAc
→
N=C(OC1O[C@H](COC(=O)c2ccccc2)[C@@H](OC(=O)c2ccccc2)[C@H](O[C@H]2O[C@H](COC(=O)c3ccccc3)[C@@H](OC(=O)c3ccccc3)[C@H](O[C@H]3O[C@H](COC(=O)c4ccccc4)[C@@H](OC(=O)c4ccccc4)[C@H](OC(=O)c4ccccc4)[C@@H]3OC(=O)c3ccccc3)[C@@H]2OC(=O)c2ccccc2)[C@@H]1OC(=O)c1ccccc1)C(Cl)(Cl)Cl
trichloroacetimidate
Ausbeute 72.2%
N=C(OC1O[C@H](COC(=O)c2ccccc2)[C@@H](OC(=O)c2ccccc2)[C@H](O[C@H]2O[C@H](COC(=O)c3ccccc3)[C@@H](OC(=O)c3ccccc3)[C@H](O[C@H]3O[C@H](COC(=O)c4ccccc4)[C@@H](OC(=O)c4ccccc4)[C@H](OC(=O)c4ccccc4)[C@@H]3OC(=O)c3ccccc3)[C@@H]2OC(=O)c2ccccc2)[C@@H]1OC(=O)c1ccccc1)C(Cl)(Cl)Cl
2,3,4,6-tetra-O-benzoyl-α-D-mannopyranosyl-(1→3)-2,4,6-tri-O-benzoyl-α-D-mannopyranosyl-(1→3)-2,4,6-tri-O-benzoyl-D-mannopyranosyl trichloroacetimidate
Ausbeute 72.2%

Edukte

O=C(OC[C@H]1O[C@H](O[C@@H]2[C@H](OC(=O)c3ccccc3)[C@@H](O[C@H]3[C@H](OC(=O)c4ccccc4)[C@@H](COC(=O)c4ccccc4)OC(O)[C@H]3OC(=O)c3ccccc3)O[C@H](COC(=O)c3ccccc3)[C@H]2OC(=O)c2ccccc2)[C@@H](OC(=O)c2ccccc2)[C@@H](OC(=O)c2ccccc2)[C@@H]1OC(=O)c1ccccc1)c1ccccc1
hemiacetal
O=C(OC[C@H]1O[C@H](O[C@@H]2[C@H](OC(=O)c3ccccc3)[C@@H](O[C@H]3[C@H](OC(=O)c4ccccc4)[C@@H](COC(=O)c4ccccc4)OC(O)[C@H]3OC(=O)c3ccccc3)O[C@H](COC(=O)c3ccccc3)[C@H]2OC(=O)c2ccccc2)[C@@H](OC(=O)c2ccccc2)[C@@H](OC(=O)c2ccccc2)[C@@H]1OC(=O)c1ccccc1)c1ccccc1
2,3,4,6-tetra-O-benzoyl-α-D-mannopyranosyl-(1→3)-2,4,6-tri-O-benzoyl-α-D-mannopyranosyl-(1→3)-2,4,6-tri-O-benzoyl-D-mannopyranose
N#CC(Cl)(Cl)Cl
trichloroacetonitrile
CCCCCC.CCOC(C)=O
hexane EtOAc

Reagenzien

C1CCC2=NCCCN2CC1
DBU

Lösungsmittel

ClCCl
DCM
ClCCl
DCM

Reaktionsbedingungen

Temperatur
0°CELSIUS
Detaillierte Bedingungen
See reaction.notes.procedure_details.

Aufarbeitung

  1. 1
    workup.ADDITIONwas added
  2. 2
    SonstigeThe crude was evaporated onto silica gel
  3. 3
    Sonstigepurified by silica column chromatography (2×14 cm, gradient elution with hexane-EtOAc 200:20, 150:30, 120:30, 150:50 and hexane-EtOAc-Et3N 140:70:0.3)

Vorschrift

The hemiacetal 52 (330 mg, 0.214 mmol) was dissolved in anhydrous DCM (1.1 mL, 0.2 M). To the solution was added trichloroacetonitrile (43 μL, 0.427 mmol, 2 eq). The mixture was stirred at 0° C. while a solution of DBU (1.6 μL, 0.05 eq, 0.0107 mmol) in anhydrous DCM (0.15 mL) was added. The mixture was stirred at 0° C. for 4 h and TLC (hexane-EtOAc=65:35) indicated the complete conversion. The crude was evaporated onto silica gel and purified by silica column chromatography (2×14 cm, gradient elution with hexane-EtOAc 200:20, 150:30, 120:30, 150:50 and hexane-EtOAc-Et3N 140:70:0.3) to give the trichloroacetimidate 53 as white foam (261 mg, 72%) which was used directly in the next step without further characterization.

Quelle

DOI: 10.6084/m9.figshare.5104873.v1Patent: US08828952B2uspto-grants-2014_09