alpha-D-Mannopyranosyl bromide, 2,3,4,6-tetraacetate → 2,3,4,6-Tetra-O-acetyl-alpha-D-mannopyranosyl fluoride

HRID 580023Notes

Reaction equation

HRID 580023 reaction equation
[C:1]([O:4][C@H:5]1[C@@H:10]([O:11][C:12](=[O:14])[CH3:13])[C@H:9]([O:15][C:16](=[O:18])[CH3:17])[C@@H:8]([CH2:19][O:20][C:21](=[O:23])[CH3:22])[O:7][C@@H:6]1Br)(=[O:3])[CH3:2].[FH:25].[F-].[K+].C(Cl)Cl.CCOCC>C(#N)C>[C:1]([O:4][C@H:5]1[C@@H:10]([O:11][C:12](=[O:14])[CH3:13])[C@H:9]([O:15][C:16](=[O:18])[CH3:17])[C@@H:8]([CH2:19][O:20][C:21](=[O:23])[CH3:22])[O:7][C@@H:6]1[F:25])(=[O:3])[CH3:2]

Participants

5

Reactant 3

HCID 11069632alpha-D-Mannopyranosyl bromide, 2,3,4,6-tetraacetateHCID 11829350Potassium bifluorideHCID 21881112Ethyl ether methylene chloride

Product 1

HCID 112681242,3,4,6-Tetra-O-acetyl-alpha-D-mannopyranosyl fluoride

Reagents, catalysts & solvents 1

HCID 6342AcetonitrileSolvent

Procedure

8.7 g (21.2 mmol) of 2,3,4,6-tetra-O-acetyl-α-D-mannopyranosyl bromide were dissolved in 30 ml of anhydrous acetonitrile and the solution was heated under reflux with 5.0 g (64 mmol) of potassium hydrogen difluoride. After 3 hours, the starting material was no longer detectable (TLC: methylene chloride/ether, 9:1). The solution was filtered and concentrated and the crude product was recrystallized from ether. Yield 5.74 g (77%), melting point 65°-67° C., [α]D20 =+21.2 (c=1.07 in chloroform) [A. Bertho, loc. cit.: melting point 68°-69° C., [α]DS20 =+21.5 (chloroform)]. 1H NMR (CDCl3): δ=5.58 (dd, 1-H), J1,2 =1.9, J1,F =48.4 Hz; [L. D. Hall et al., Can. J. Chem. 47, 1 (1969): δ=5.57 (dd, 1-H), J1.2 =1.7, J1,F =48.6 Hz].

Workup

  1. temperaturethe solution was heated
  2. filtrationThe solution was filtered
  3. concentrationconcentrated
  4. customthe crude product was recrystallized from ether

Sources & evidence

ORD record
ord-94ac63d829514c1b94128bbdf9ed9634
Source dataset
uspto-grants-1988_06
Patent number
US04751291

Reaction notes

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