Dabco → benzyl 2-acetamido-4-O-(2-acetamido-3,4,6-tri-O-benzyl-2-deoxy-beta-D-glucopyranosyl)-6-O-benzyl-2-deoxy-alpha-D-glucopyranoside

HRID 1074433Notes

Reaction equation

HRID 1074433 reaction equation
[C:1]([NH:4][C@@H:5]1[C@@H:18]([O:19]CC=C)[C@H:17]([O:23][C@@H:24]2[O:45][C@H:44]([CH2:46][O:47][CH2:48][C:49]3[CH:54]=[CH:53][CH:52]=[CH:51][CH:50]=3)[C@@H:35]([O:36][CH2:37][C:38]3[CH:43]=[CH:42][CH:41]=[CH:40][CH:39]=3)[C@H:26]([O:27][CH2:28][C:29]3[CH:34]=[CH:33][CH:32]=[CH:31][CH:30]=3)[C@H:25]2[NH:55][C:56](=[O:58])[CH3:57])[C@@H:16]([CH2:59][O:60][CH2:61][C:62]2[CH:67]=[CH:66][CH:65]=[CH:64][CH:63]=2)[O:15][C@@H:6]1[O:7][CH2:8][C:9]1[CH:14]=[CH:13][CH:12]=[CH:11][CH:10]=1)(=[O:3])[CH3:2].N12CCN(CC1)CC2>[Rh].[Rh]Cl.C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1>[C:1]([NH:4][C@@H:5]1[C@@H:18]([OH:19])[C@H:17]([O:23][C@@H:24]2[O:45][C@H:44]([CH2:46][O:47][CH2:48][C:49]3[CH:50]=[CH:51][CH:52]=[CH:53][CH:54]=3)[C@@H:35]([O:36][CH2:37][C:38]3[CH:43]=[CH:42][CH:41]=[CH:40][CH:39]=3)[C@H:26]([O:27][CH2:28][C:29]3[CH:30]=[CH:31][CH:32]=[CH:33][CH:34]=3)[C@H:25]2[NH:55][C:56](=[O:58])[CH3:57])[C@@H:16]([CH2:59][O:60][CH2:61][C:62]2[CH:63]=[CH:64][CH:65]=[CH:66][CH:67]=2)[O:15][C@@H:6]1[O:7][CH2:8][C:9]1[CH:14]=[CH:13][CH:12]=[CH:11][CH:10]=1)(=[O:3])[CH3:2]

Participants

5

Reactant 2

HCID 9237DabcoHCID 10930998benzyl 2-acetamido-4-O-(2-acetamido-3,4,6-tri-O-benzyl-2-deoxy-beta-D-glucopyranosyl)-3-O-allyl-6-O-benzyl-2-deoxy-alpha-D-glucopyranoside

Product 1

HCID 14129574benzyl 2-acetamido-4-O-(2-acetamido-3,4,6-tri-O-benzyl-2-deoxy-beta-D-glucopyranosyl)-6-O-benzyl-2-deoxy-alpha-D-glucopyranoside

Reagents, catalysts & solvents 2

HCID 23948RhodiumCatalystHCID 178479813HCID 178479813, compoundCatalyst

Procedure

To a solution of benzyl 2-acetamido-4-O-(2-acetamido-3,4,6-tri-O-benzyl-2-deoxy-β-D-glucopyranosyl)-3-O-allyl-6-O-benzyl-2-deoxy-α-D-glucopyranoside (597 mg, 0.65 mmol) in 7:3:1 (v/v/v) ethanol-toluene-water (25 ml) stirred at reflux temperature under an atmosphere of nitrogen are added 1,4-diazabicyclo[2.2.2] octane (75 mg, 0.67 mmol) and tris(triphenylphosphine) rhodium (I) chloride (50 mg). Two further additions of 50 mg of the rhodium catalyst are made at 90 minute intervals, and stirring at reflux temperature under nitrogen is continued overnight. The cooled solution is then evaporated, the residue taken up in chloroform (80 ml), washed three times with water, dried (magnesium sulfate), and evaporated. The residue is then stirred in aqueous (1.5 ml) tetrahydrofuran (15 ml) in the presence of mercuric chloride (750 mg) for 30 minutes at room temperature. The reaction mixture is then evaporated, the residue taken up in chloroform (75 ml), washed twice with 2.5 M aqueous potassium iodide, dried (magnesium sulfate) and evaporated to a residue that is applied to a column of silica gel (40 g) that is eluted with 2:1 chloroform-ethyl acetate. Combination and evaporation of the appropriate fractions affords benzyl 2-acetamido-4-O-(2-acetamido-3,4,6-tri-O-benzyl-2-deoxy-β-D-glucopyranosyl)-6-O-benzyl-2-deoxy-α-D-glucopyranoside; yield 362 mg (63%); m.p. 220.5°-221.5° (methanol), [α]D25 +74° (c, 1.5, chloroform). The 300 MHz nmr spectrum in chloroform-d is in accord with the desired structure.

Workup

  1. temperatureat reflux temperature under an atmosphere of nitrogen
  2. temperatureat reflux temperature under nitrogen
  3. customThe cooled solution is then evaporated
  4. washwashed three times with water
  5. dry with materialdried (magnesium sulfate)
  6. customevaporated
  7. stirringThe residue is then stirred in aqueous (1.5 ml) tetrahydrofuran (15 ml) in the presence of mercuric chloride (750 mg) for 30 minutes at room temperature
  8. customThe reaction mixture is then evaporated
  9. washwashed twice with 2.5 M aqueous potassium iodide
  10. dry with materialdried (magnesium sulfate)
  11. customevaporated to a residue that
  12. washis eluted with 2:1 chloroform-ethyl acetate
  13. customCombination and evaporation of the appropriate fractions

Sources & evidence

ORD record
ord-65ca9517f91e46feb3c0d6ab9de6c31b
Source dataset
uspto-grants-1983_07
Patent number
US04391800

Reaction notes

Loading…