Reaktion #10260

Reaktionsgleichung

Diisobutylaluminum hydride

ester

(3R,5R)-3,5-Bis[(tert-butyldimethylsilyl)oxy]-1-hydroxy-4-methylenecyclohexanecarboxylic Acid Methyl Ester

→

diol

Ausbeute 24.0%

[(3R,5R)-3,5-Bis[(tert-butyldimethylsilyl)oxy]-1-hydroxy-4-methylenecyclohexyl]methanol

Ausbeute 24.0%

Lösungsmittel

ether

ether

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigequenched by the slow addition of 2N potassium sodium tartrate
2. 2
   TemperaturThe solution was warmed to room temperature
3. 3
   workup.STIRRINGstirred for 15 min
4. 4
   workup.ADDITIONpoured into brine
5. 5
   Extraktionextracted with ethyl acetate and ether
6. 6
   Waschenwashed
7. 7
   workup.ADDITIONwith diluted (ca. 1%) HCl, and brine
8. 8
   Trocknendried (MgSO4)
9. 9
   Sonstigeevaporated
10. 10
    SonstigeThe crystalline residue was purified by flash chromatography
11. 11
    WaschenElution with hexane/ethyl acetate (9:1)

Vorschrift

Diisobutylaluminum hydride (1.5 M in toluene, 2.0 mL, 3 mmol) was added to a solution of the ester 3 (215 mg, 0.5 mmol) in anhydrous ether (3 mL) at −78° C. under argon. The mixture was stirred at −78° C. for 3 h and at −24° C. for 1.5 h, diluted with ether (10 mL) and quenched by the slow addition of 2N potassium sodium tartrate. The solution was warmed to room temperature and stirred for 15 min, then poured into brine and extracted with ethyl acetate and ether. The organic extracts were combined, washed with diluted (ca. 1%) HCl, and brine, dried (MgSO4) and evaporated. The crystalline residue was purified by flash chromatography. Elution with hexane/ethyl acetate (9:1) gave crystalline diol 4 (43 mg, 24%).

Quelle