Diisopropylamine → 8-t-Butyldimethylsilyloxy-1-(2,2-Dimethyl-1,3-Dioxolan-4-yl)-2-Hydroxyoctan-4-One
Reaktionsgleichung
C([Li])CCC.CCCCCC.C(NC(C)C)(C)C.[Si:19]([O:26][CH2:27][CH2:28][CH2:29][CH2:30][C:31](=[O:33])[CH3:32])([C:22]([CH3:25])([CH3:24])[CH3:23])([CH3:21])[CH3:20].[CH3:34][C:35]1([CH3:43])[O:39][CH:38]([CH2:40][CH:41]=[O:42])[CH2:37][O:36]1>C1COCC1.O>[Si:19]([O:26][CH2:27][CH2:28][CH2:29][CH2:30][C:31](=[O:33])[CH2:32][CH:41]([OH:42])[CH2:40][CH:38]1[CH2:37][O:36][C:35]([CH3:43])([CH3:34])[O:39]1)([C:22]([CH3:25])([CH3:24])[CH3:23])([CH3:21])[CH3:20]Komponenten
Edukt 5
Produkt 1
Reagenzien, Katalysatoren, Lösungsmittel 2
Versuchsvorschrift
A solution of n-butyl lithium in hexane (119 ml, 1.6M, 0.19 mol) is added dropwise to a solution of diisopropylamine (19.3 g, 0.191 mol) in THF (100 ml) cooled in an ice bath. After the addition, the mixture is stirred for 20 minutes then cooled to -78°. A solution of 6-t-butyldimethylsilyloxy-hexan-2-one (40.0 g, 0.174 mol) in THF is added dropwise. The resultant mixture is stirred for 90 minutes then a solution of 2,2-dimethyl-1,3-dioxolane-4-acetaldehyde (25.1 g, 0.174 mol) in THF (100 ml) is added dropwise. After the addition, the mixture is stirred for 2 hours, then water (10 ml) slowly added. The mixture is warmed to 0°, diluted with water (300 ml) and extracted with ether (2×500 ml). The extracts are washed with saturated brine, dried over sodium sulfate and concentrated under reduced pressure to leave the crude product (63.5 g) an oil. A portion of this material (46 g) is chromatographed on silica gel (2.5 Kg) eluting with 25% ethyl acetate/hexane to give the title compound, 8-t-butyldimethylsilyloxy-1-(2,2-dimethyl-1,3-doxolan-4-yl)-2-hydroxyoctan-4-one; (23 g, 49%) an oil.
Aufarbeitung
- temperaturecooled in an ice bath
- additionAfter the addition
- temperaturethen cooled to -78°
- additionAfter the addition
- stirringthe mixture is stirred for 2 hours
- temperatureThe mixture is warmed to 0°
- extractionextracted with ether (2×500 ml)
- washThe extracts are washed with saturated brine
- dry with materialdried over sodium sulfate
- concentrationconcentrated under reduced pressure
- customto leave the crude product (63.5 g) an oil
- customA portion of this material (46 g) is chromatographed on silica gel (2.5 Kg)
- washeluting with 25% ethyl acetate/hexane
Quellen und Nachweise
- ORD-Eintrag
- ord-d281ede4768c447887f8d1e077b75f5f
- Quelldatensatz
- uspto-grants-1987_08
- Patentnummer
- US04686297
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