Reaktion #2637

Reaktionsgleichung

lithium aluminum hydride

4-tert-butyldimethylsiloxy-2-cyclopentenone

lithium iodide

→

title compound

Ausbeute 80.0%

cis-4-tert-butyldimethylsilyloxy-2-cyclopentenol

Ausbeute 80.0%

Lösungsmittel

ethyl ether

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeIt is then quenched by slow addition of aqueous sodium hydroxide (1N, 23 mL) at a rate
2. 2
   Sonstigethe temperature of the reaction below 20° C
3. 3
   FiltrationThe resulting suspension is then filtered through a pad of diatomaceous earth
4. 4
   Waschenthe pad is subsequently rinsed with ether
5. 5
   SonstigeThe filtrate phases are separated
6. 6
   Extraktionthe aqueous phase is extracted with ether (20 mL)
7. 7
   ExtraktionThe organic phase and organic extract
8. 8
   Waschenrinsed with aqueous sodium hydroxide (1N, 20 mL), brine (20 mL)
9. 9
   Trocknendried over anhydrous magnesium sulfate
10. 10
    Filtrationfiltered
11. 11
    Einengenconcentrated under vacuum (40° C., 20 mmHg)
12. 12
    workup.DISTILLATIONThe residue is then purified by Kugelrohr distillation (60°-80° C., 1 mmHg)

Vorschrift

A mechanically stirred solution of 4-tert-butyldimethylsiloxy-2-cyclopentenone (1.01 g, 4.76 mmol) in anhydrous ethyl ether (20 mL) under an atmosphere of argon is treated with lithium iodide (3.20 g, 23.9 mmol). The mixture is cooled to -78° C. and treated with lithium aluminum hydride (184 mg, 4.85 mmol) in one portion. The reaction is then stirred for 90 minutes. It is then quenched by slow addition of aqueous sodium hydroxide (1N, 23 mL) at a rate that maintains the temperature of the reaction below 20° C. The resulting suspension is then filtered through a pad of diatomaceous earth and the pad is subsequently rinsed with ether. The filtrate phases are separated and the aqueous phase is extracted with ether (20 mL). The organic phase and organic extract are combined, rinsed with aqueous sodium hydroxide (1N, 20 mL), brine (20 mL), dried over anhydrous magnesium sulfate, filtered and concentrated under vacuum (40° C., 20 mmHg). The residue is then purified by Kugelrohr distillation (60°-80° C., 1 mmHg) to provide the title compound. (820 mg, 80% yield) as a colorless oil; cis/trans/1-2+1-4 addition, 88.5/3.3/8.2.

Quelle