((2S,4R)-4-(tert-butyldimethylsilyloxy)-6-oxotetrahydro-2H-pyran-2-yl)methyl acetate → (4R,6S)-4-(tert-butyldimethylsilyloxy)-6-(hydroxymethyl)-tetrahydropyran-2-one
Reaction equation
C([O:4][CH2:5][C@@H:6]1[CH2:11][C@@H:10]([O:12][Si:13]([C:16]([CH3:19])([CH3:18])[CH3:17])([CH3:15])[CH3:14])[CH2:9][C:8](=[O:20])[O:7]1)(=O)C>CO.C1COCC1>[Si:13]([O:12][C@@H:10]1[CH2:11][C@@H:6]([CH2:5][OH:4])[O:7][C:8](=[O:20])[CH2:9]1)([C:16]([CH3:19])([CH3:18])[CH3:17])([CH3:15])[CH3:14]Participants
Conditions
- Temperature
- 24 °C
Procedure
(2S,4R)-4-(tert-butyldimethylsilyloxy)-6-oxo-tetrahydro-2H-pyran-2-yl)methyl acetate (7) (8.36 g, 27.64 mmol) and [t-Bu2SnOH(Cl)]2 (1.577 g, 2.764 mmol) are dissolved in MeOH/THF mixture (280 mL). The reaction mixture is stirred at 23-25° C. for 27 h. The solvent is removed under reduced pressure and the remaining residue is purified by silica gel chromatography (elution with t-BuMeO/hexane mixture) to afford a crude product as white solid (5.59 g, 78%). Recrystallization from n-hexane affords (3.90 g, 54%) of (4R,6S)-4-(tert-butyldimethylsilyloxy)-6-(hydroxymethyl)-tetrahydro-pyran-2-one (8) as white needles. M.p.=102° C. (DSC peak). 1H NMR (300 MHz, CDCl3) δ: 4.80 (m, 1H), 4.38 (m, 1H), 3.91 (dd, J=12 Hz, J=3 Hz, 1H), 3.66 (dd, J=12 Hz, J=5 Hz, 1H), 2.60 (d, J=4 Hz, 2H), 2.31 (bs, 1H), 1.97−1.75 (m, 2H), 0.88 (s, 9H), 0.09, 0.08 (2s, 6H). 13C NMR (75 MHz, CDCl3) δ: 170.1, 76.8, 64.7, 63.4, 39.2, 31.9, 25.6, 17.9, −4.9, −5.0.
Workup
- customThe solvent is removed under reduced pressure
- customthe remaining residue is purified by silica gel chromatography (
- washelution with t-BuMeO/hexane mixture)
- customto afford a crude product as white solid (5.59 g, 78%)
- customRecrystallization from n-hexane
Sources & evidence
- ORD record
- ord-3ea3fa052dcc495c8ae40be13a4b3071
- Source dataset
- uspto-grants-2012_09
- Patent number
- US08269001B2
Reaction notes
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