Trichloroacetonitrile → O-(2,3,4-tri-O-acetyl-beta-L-fucopyranosyl) trichloroacetimidate

HRID 1491955Notes

Reaction equation

HRID 1491955 reaction equation
[C:1]([O:4][C@H:5]1[C@H:11]([O:12][C:13](=[O:15])[CH3:14])[C@H:10]([O:16][C:17](=[O:19])[CH3:18])[C@H:9]([CH3:20])[O:8][CH:6]1[OH:7])(=[O:3])[CH3:2].[Cl:21][C:22]([Cl:26])([Cl:25])[C:23]#[N:24].C(=O)([O-])[O-].[K+].[K+]>ClCCl>[Cl:21][C:22]([Cl:26])([Cl:25])[C:23](=[NH:24])[O:7][C@H:6]1[O:8][C@@H:9]([CH3:20])[C@@H:10]([O:16][C:17](=[O:19])[CH3:18])[C@@H:11]([O:12][C:13](=[O:15])[CH3:14])[C@@H:5]1[O:4][C:1](=[O:3])[CH3:2]

Participants

5

Reactant 3

HCID 11011TrichloroacetonitrileHCID 11430Potassium CarbonateHCID 10979132GlyTouCan:G58715BY

Product 1

HCID 14216865O-(2,3,4-tri-O-acetyl-beta-L-fucopyranosyl) trichloroacetimidateYield 76%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

A mixture of 2,3,4-tri-O-acetyl-L-fucopyranose (anomer mixture) (0.85 g, 2.93 mmol), trichloroacetonitrile (3 ml, 30 mmol) and potassium carbonate (2.73 g, 19.7 mmol) in dry dichloromethane (12 ml) is stirred under nitrogen at room temperature for about 4 h. After filtration through kieselguhr, the solvent is removed. After chromatographic purification (petroleum ether/diethyl ether 2:5), a mixture of O-(2,3,4-tri-O-acetyl-α-L-fucopyranosyl) trichloroacetimidate (3) and O-(2,3,4-tri-O-acetyl-β-L-fucopyranosyl) trichloroacetimidate (2) is obtained in a yield of 76% (α:β=1:1.3). α-Anomer: [α]D =-116.0 (c=1, chloroform), Rf =0.54 (petroleum ether/ethyl acetate 2:1), m.p. 107°-109° C. β-Anomer: [α]D =-24.5 (c=1, chloroform), Rf =0.34 (petroleum ether/ethyl acetate 2:1), m.p. 60°-63° C.

Workup

  1. filtrationAfter filtration through kieselguhr
  2. customthe solvent is removed
  3. customAfter chromatographic purification (petroleum ether/diethyl ether 2:5)
  4. additiona mixture of O-(2,3,4-tri-O-acetyl-α-L-fucopyranosyl) trichloroacetimidate (3)

Sources & evidence

ORD record
ord-744d60b1741241adb140e88e4d86c6d3
Source dataset
uspto-grants-1994_12
Patent number
US05371203

Reaction notes

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