4-Hydroxybenzaldehyde → (2S,4R,5R)-2-benzhydryl-5-(4-hydroxy-benzylamino)-tetrahydropyran-4-ol
Reaction equation
[NH2:1][C@@H:2]1[CH2:7][O:6][C@H:5]([CH:8]([C:15]2[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=2)[C:9]2[CH:14]=[CH:13][CH:12]=[CH:11][CH:10]=2)[CH2:4][C@H:3]1[OH:21].[OH:22][C:23]1[CH:30]=[CH:29][C:26]([CH:27]=O)=[CH:25][CH:24]=1.C(O)(=O)C.[BH3-]C#N.[Na+].C([O-])(O)=O.[Na+]>ClCCCl.CO.O>[CH:8]([C@@H:5]1[CH2:4][C@@H:3]([OH:21])[C@H:2]([NH:1][CH2:27][C:26]2[CH:29]=[CH:30][C:23]([OH:22])=[CH:24][CH:25]=2)[CH2:7][O:6]1)([C:9]1[CH:14]=[CH:13][CH:12]=[CH:11][CH:10]=1)[C:15]1[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=1Participants
Reactant 5
Product 1
Reagents, catalysts & solvents 3
Conditions
- Temperature
- 0 °C
Procedure
To a solution of (2S,4R,5R)-5-amino-2-benzhydryl-tetrahydro-pyran-4-ol 31a (0.02 g, 0.09 mmol), 4-hydroxybenzaldehyde (0.01 g, 0.09 mmol) and glacial acetic acid (0.005 g, 0.09 mmol) in 1,2-dichloroethane (5 ml) was added portionwise NaCNBH3 (0.007 g, 0.11 mmol) in methanol (1 ml). The reaction was continued for 4 hr. Water was added to quench the reaction and the mixture was stirred for 30 minutes at 0° C. The reaction mixture was stirred with saturated aqueous NaHCO3 and the product was extracted with methylene chloride (3×10 ml). The combined organic phases were washed with brine, water and dried over anhydrous Na2SO4. Solvent was removed under reduced pressure, and the residue was purified by flash chromatography (Hexane/Ethyl Acetate/Triethylamine 3:2:0.2) to give (2S,4R,5R)-2-benzhydryl-5-(4-hydroxy-benzylamino)-tetrahydropyran-4-ol, (−)-32a, 0.03 g (80%, [α]D=(−)72.6, c=1, MeOH).
Workup
- customto quench
- customthe reaction
- extractionthe product was extracted with methylene chloride (3×10 ml)
- washThe combined organic phases were washed with brine, water
- dry with materialdried over anhydrous Na2SO4
- customSolvent was removed under reduced pressure
- customthe residue was purified by flash chromatography (Hexane/Ethyl Acetate/Triethylamine 3:2:0.2)
Sources & evidence
- ORD record
- ord-c83b12e814c94babb587ef386935534a
- Source dataset
- uspto-grants-2015_01
- Patent number
- US08937189B2
Reaction notes
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