alpha-D-Galactopyranosyl bromide, tetraacetate → HCID 21362958, compound

HRID 1169010Notes

Reaction equation

HRID 1169010 reaction equation
[CH3:1][C:2]([O:4][CH2:5][CH:6]1[O:11][CH:10](Br)[CH:9]([O:13][C:14]([CH3:16])=[O:15])[CH:8]([O:17][C:18]([CH3:20])=[O:19])[CH:7]1[O:21][C:22]([CH3:24])=[O:23])=[O:3].[CH3:25][S:26](=[S:29])([O-:28])=[O:27].[Na+]>C1(C)C=CC=CC=1>[CH3:25][S:26](=[S:29])([O:28][C@@H:10]1[O:11][C@H:6]([CH2:5][O:4][C:2](=[O:3])[CH3:1])[C@H:7]([O:21][C:22](=[O:23])[CH3:24])[C@H:8]([O:17][C:18](=[O:19])[CH3:20])[C@H:9]1[O:13][C:14](=[O:15])[CH3:16])=[O:27]

Participants

4

Reactant 2

HCID 102932alpha-D-Galactopyranosyl bromide, tetraacetateHCID 23688755Methanesulfonothioic acid, sodium salt

Product 1

HCID 21362958HCID 21362958, compoundYield 67%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

Acetobromogalactose 1 (1.1 g, 2.68 mmol) and sodium methanethiosulfonate (0.45 g, 3.35 mmol) in toluene (50 mL) were concentrated in vacuo to approximately 30 mL to remove any water as the azeotrope. The mixture was made up to 50 mL with more toluene and again concentrated to 30 mL. A catalytic amount of tetrabutylammonium iodide was added and the mixture heated at reflux for 75 minutes. After cooling, Celite (to stop the formation of a salt cake on top of the column) was added and the whole mixture loaded directly on to a flash silica column. Elution with 40% ethyl acetate in petroleum ether and recrystallization from petroleum ether/ethyl acetate gave the title compound (787 mg, 67%) as colorless prisms; mp 118-119° C. (petroleum ether/ethyl acetate); [α]23D=+8.5 (c 1.0, CHCl3); IR (KBr) 1753 (C═O), 1325, 1138 (S—SO2) cm−1;1H NMR (400 MHz, CDCl3) δ 1.99 (s, 3H, Ac), 2.50 (s, 3H, Ac), 2.08 (s, 3H, Ac), 2.17 (s, 3H, Ac), 3.43 (s, 3H, CH3SO2—), 4.05 (ddd, J 7.4, 4.2, 0.9 Hz, 1 H), 4.08 (dd, J 18.3, 7.5 Hz, 1H), 4.20 (dd, J 10.8, 4.3 Hz, 1H), 5.13 (dtd, J 10.7, 7.6, 3.4 Hz, 1H), 5.26 (s, 1H), 5.27 (dd, J 14.8, 10.3 Hz, 1H), 5.48 (dd, J 3.4, 0.8 Hz, 1H); 13C NMR (100 MHz, CDCl3) δ 20.5, 20.6, 20.6, 20.6 (4×CH3CO), 52.7 (CH3SO2—), 61.8 (C-6), 65.8, 67.0, 71.3, 75.3, 87.0 (1J1CH 165 Hz, C-1), 169.7, 169.7, 170.0, 170.2 (4×C═O); HRMS m/z (ES): found 460.0951; C15H26NO11S2 requires 460.0947.

Workup

  1. customto remove any water as the azeotrope
  2. concentrationagain concentrated to 30 mL
  3. additionA catalytic amount of tetrabutylammonium iodide was added
  4. temperaturethe mixture heated
  5. temperatureat reflux for 75 minutes
  6. temperatureAfter cooling
  7. additionwas added
  8. washElution
  9. customwith 40% ethyl acetate in petroleum ether and recrystallization from petroleum ether/ethyl acetate

Sources & evidence

ORD record
ord-063667ba571743e08d2013e5d080841e
Source dataset
uspto-grants-2003_09
Patent number
US06627744B2

Reaction notes

Loading…