3,4-dihydro-2H-pyran → HCID 66978150, compound
Reaction equation
[OH:1][C:2]1[CH:3]=[C:4]2[C:9](=[C:10]([CH3:13])[C:11]=1[CH3:12])[O:8][C:7]([CH2:15][CH2:16][C:17]([OH:19])=O)([CH3:14])[CH2:6][CH2:5]2.[O:20]1[CH:25]=[CH:24][CH2:23][CH2:22][CH2:21]1.[H-].[H-].[H-].[H-].[Li+].[Al+3]>ClCCl.C1COCC1.C1(C)C=CC(S([O-])(=O)=O)=CC=1.[NH+]1C=CC=CC=1>[CH3:14][C:7]1([CH2:15][CH2:16][CH2:17][OH:19])[CH2:6][CH2:5][C:4]2[C:9](=[C:10]([CH3:13])[C:11]([CH3:12])=[C:2]([O:1][CH:21]3[CH2:22][CH2:23][CH2:24][CH2:25][O:20]3)[CH:3]=2)[O:8]1Participants
Reactant 3
Product 1
Reagents, catalysts & solvents 3
Procedure
A mixture of 3-(6-hydroxy-2,7,8-trimethyl-chroman-2-yl)-propionic acid (500 mg), 3,4-dihydro-2-H-pyran (2 mL) and pyridinium p-toluenesulfonate (PPTS) (50 mg) in dichloromethane (20 mL) was stirred at RT for overnight. The mixture was washed with water, dried over MgSO4, and concentrated to give an oily residue. The oil was dissolved in THF, then LiAlH4 (85 mg) was added and the mixture was stirred at RT for 2 h. The excess LiAlH4 was destroyed by adding ethyl acetate, and the mixture was poured into water and extracted with EtOAc. The organic layer was washed with water, dried over MgSO4, and concentrated. The residue was purified by silica gel column chromatography eluting with 30% EtOAc in hexane to give 732 mg of 3-[2,7,8-trimethyl-6-(tetrahydro-pyran-2-yloxy)-chroman-2-yl]-propan-1-ol as an oily product. 1H-NMR (300 MHz, CDCl3) δ (ppm): 6.67 (s, 1H), 5.32 (t, J=3.2 MHz, 1H), 4.0-3.9 (m, 1H), 3.70-3.55 (m, 3H), 2.75-2.70 (m, 2H), 2.15, 2.09 (2s, 6H), 2.10-1.60 (m, 12H), 1.25 (s, 3H). 13C-NMR (75 MHz, CDCl3) δ (ppm): 148.08, 146.23, 125.51, 125.25, 117.66, 112.99, 112.96, 97.36, 75.17, 63.25, 62.09, 60.41, 36.26, 36.03, 31.51, 31.47, 30.78, 26.97, 25.41, 24.01, 23.81, 22, 48, 21.05, 19.11, 14.19, 12.18, 11.94.
Workup
- washThe mixture was washed with water
- dry with materialdried over MgSO4
- concentrationconcentrated
- customto give an oily residue
- stirringthe mixture was stirred at RT for 2 h
- customThe excess LiAlH4 was destroyed
- additionby adding ethyl acetate
- additionthe mixture was poured into water
- extractionextracted with EtOAc
- washThe organic layer was washed with water
- dry with materialdried over MgSO4
- concentrationconcentrated
- customThe residue was purified by silica gel column chromatography
- washeluting with 30% EtOAc in hexane
Sources & evidence
- ORD record
- ord-9da7adfecbf5423681ded0111b1ee2b5
- Source dataset
- uspto-grants-2011_10
- Patent number
- US08044097B2
Reaction notes
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