Reaction #90567

Reaction equation

317

Allyl (3,4,6-tri-O-acetyl-2-deoxy-2-trichloroacetamido-β-D-glucopyranosyl)-(1→2)-3,4-di-O-benzyl-α-L-rhamnopyranoside

→

318

Yield 83.1%

(3,4,6-tri-O-acetyl-2-deoxy-2-trichloroacetamido-β-D-glucopyranosyl)-(1→2)-3,4-di-O-benzyl-α-L-rhamnopyranose

Yield 83.1%

Solvents

tetrahydrofuran

tetrahydrofuran

Conditions

Workup

1. 1
   Otherthe resulting red solution was degassed in an argon stream
2. 2
   OtherHydrogen was then bubbled through the solution
3. 3
   OtherThe solution was then degassed again in an argon stream
4. 4
   workup.ADDITIONadded
5. 5
   ConcentrationThe mixture was concentrated
6. 6
   workup.ADDITIONwater (3 mL) was added
7. 7
   workup.STIRRINGThe mixture was stirred for 2 h at rt
8. 8
   Concentrationconcentrated
9. 9
   Washwashed three limes with sat. aq. KI
10. 10
    OtherThe organic phase was dried
11. 11
    Concentrationconcentrated
12. 12
    OtherThe residue was purified by column chromatography (cyclohexane-EtOAc 4:1)

Procedure

1,5-Cyclooctadiene-bis(methyldiphenylphosphine)iridium hexafluorophosphate (120 mg, 140 μmol) was dissolved tetrahydrofuran (10 mL), and the resulting red solution was degassed in an argon stream. Hydrogen was then bubbled through the solution, causing the colour to change to yellow. The solution was then degassed again in an argon stream. A solution of 317 (1.46 g, 1.75 mmol) in tetrahydrofuran (20 mL) was degassed and added. The mixture was stirred at rt overnight. The mixture was concentrated. The residue was taken up in acetone (27 mL), and water (3 mL) was added. Mercuric bromide (949 mg, 2.63 mmol) and mercuric oxide (761 mg, 3.5 mmol) were added to the mixture, protected from light. The mixture was stirred for 2 h at rt, then concentrated. The residue was taken up in CH2Cl2 and washed three limes with sat. aq. KI, then with brine. The organic phase was dried and concentrated. The residue was purified by column chromatography (cyclohexane-EtOAc 4:1) to give 318 (1.13 g, 81%) as a white foam. [α]D+4° (c 1, CHCl3). 1H NMR: δ 7.35-7.05 (m, 10H, Ph), 6.74 (d, 1H, J2,NH=8.5 Hz, NHD), 5.10 (d, 1H, J1,2=1.1 Hz, H-1A), 5.02 (m, 2H, H-3D, 4D), 4.80-4.50 (m, 4H, CH2Ph), 4.61 (d, 1H, J1,2=8.5 Hz, H-1D), 4.15-4.08 (m, 2H, J5,6=4.5, J6a,6b=12.3 Hz, H-6aD, 6bD), 4.00 (m, 1H, H-2D), 3.90 (dd, 1H, J2,3=3.3, H-2A), 3.86 (dd, 1H, J3,4=9.5 Hz, H-3A), 3.85 (dq, 1H, J4,5=9.5, J5,6=6.2 Hz, H-5A), 3.50 (m, 1H, H-5D), 3.30 (pt, 1H, H-4A), 2.85 (d, 1H, J1,OH=3.5 Hz, OH), 2.02, 1.97, 1.94 (3s, 9H, OAc), 1.23 (d, 3H, H-6A); 13C NMR: δ 171.1, 170.0, 169.6, 162.1 (C═O), 138.5-127.1 (Ph), 101.7 (C-1D), 94.1 (C-1A), 92.6 (CCl3), 81.4 (C-4A), 79.9 (C-2A), 77.3 (C-3A), 75.9, 74.1 (2C, CH2Ph), 72.7 (C-3D), 72.5 (C-5D), 68.6 (C-4D), 68.4 (C-5A), 62.2 (C-6D), 56.1 (C-2D), 21.1, 21.0, 20.9 (3C, OAc), 18.3 (C-6A). FAB-MS for C34H40Cl3NO13 (M, 775), m/z 789 [M+Na]+. Anal. Calcd for C34H40Cl3NO13: C, 52.55; H, 5.19; N, 1.80%. Found: C, 52.48; H, 5.37; N, 1.67%.

Source