p-Toluenesulfonic acid → HCID 57824504, compound
Reaction equation
C([O:8][C@H:9]1[C@H:14]([CH3:15])[O:13][C@@H:12]([OH:16])[C@H:11]([O:17][CH3:18])[C@@H:10]1[O:19][CH3:20])C1C=CC=CC=1.O[N:22]1[C:26](=[O:27])[CH2:25][CH2:24][C:23]1=[O:28].CC1C=CC(S(O)(=O)=O)=CC=1.[H][H]>C1C=CC=CC=1.CCO.[OH-].[OH-].[Pd+2].O>[OH:8][C@H:9]1[C@H:14]([CH3:15])[O:13][C@@H:12]([O:16][N:22]2[C:26](=[O:27])[CH2:25][CH2:24][C:23]2=[O:28])[C@H:11]([O:17][CH3:18])[C@@H:10]1[O:19][CH3:20]Participants
Reactant 4
Product 1
Reagents, catalysts & solvents 4
Procedure
A solution of (2R,3R,4R,5S,6S)-5-benzyloxy-3,4-dimethoxy-6-methyl-tetrahydropyran-2-ol (prepared according to Wu et al., Carbohydr. Res. 1998, 306, 493; 10.5 g, 26.6 mmol), N-hydroxysuccinimide (5.0 g, 50 mmol) and TsOH (250 mg, cat.) in benzene (100 mL) was heated at reflux for 24 h with removal of H2O using a Dean-Stark trap. The brown solution was cooled, filtered, washed with saturated NaHCO3 solution and concentrated. The gummy oil was purified by silica gel chromatography, eluting with 70:30 hexanes-acetone. The pure O-succinimide (7.5 g, 14.5 mmol) was then transferred to a 500-mL Parr hydrogenation apparatus and debenzylated using Pd(OH)2/C (0.95 g) in EtOH (75 mL). The solution, which took up 19 pounds per square inch (psi) of hydrogen over 24 h, was then filtered and concentrated, leaving a solid residue which was recrystallized from EtOH to give a white solid (3.25 g).
Workup
- temperatureThe brown solution was cooled
- filtrationfiltered
- washwashed with saturated NaHCO3 solution
- concentrationconcentrated
- customThe gummy oil was purified by silica gel chromatography
- washeluting with 70:30 hexanes-acetone
- customover 24 h
- filtrationwas then filtered
- concentrationconcentrated
- customleaving a solid residue which
- customwas recrystallized from EtOH
Sources & evidence
- ORD record
- ord-c78a2226add24ac78fbeff6c8e88015e
- Source dataset
- uspto-grants-2013_03
- Patent number
- US08394774B2
Reaction notes
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