Reaction #2638

Reaction equation

tert-butyl methyl ether

4-tert-butyldimethylsiloxy-2-cyclopentenone

lithium bromide

lithium aluminum hydride

→

title compound

Yield 69.2%

cis-4-tert-butyldimethylsilyloxy-2-cyclopentenol

Yield 69.2%

Solvents

toluene

Conditions

Workup

1. 1
   OtherIt is then quenched by slow addition of aqueous sodium hydroxide (1N, 7.0 mL) at a rate
2. 2
   Otherthe temperature of the reaction below 20° C
3. 3
   FiltrationThe resulting suspension is then filtered through a pad of diatomaceous earth
4. 4
   Washthe pad is subsequently rinsed with toluene
5. 5
   OtherThe filtrate phases are separated
6. 6
   Extractionthe aqueous phase is extracted with toluene
7. 7
   ExtractionThe organic phase and organic extract
8. 8
   Washrinsed with aqueous sodium hydroxide (1N), brine
9. 9
   Dryingdried over anhydrous magnesium sulfate
10. 10
    Filtrationfiltered
11. 11
    Concentrationconcentrated under vacuum (40° C., 20 mmHg)
12. 12
    workup.DISTILLATIONThe residue is then purified by Kugelrohr distillation (60°-80° C., 1 mmHg)

Procedure

A mechanically stirred solution of 4-tert-butyldimethylsiloxy-2-cyclopentenone (501 mg, 2.36 mmol) in anhydrous toluene (10 mL) under an atmosphere of argon is treated with lithium bromide (1.06 g, 12.2 mmol). The mixture is cooled to -20° C. with an ice/salt bath and treated with lithium aluminum hydride (92.0 mg, 2.42 mmol) in one portion followed by tert-butyl methyl ether (1.0 mL). The ice/salt bath is replaced with an ice bath and the reaction is then stirred for 2 hours at 0° C. It is then quenched by slow addition of aqueous sodium hydroxide (1N, 7.0 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 toluene. The filtrate phases are separated and the aqueous phase is extracted with toluene. The organic phase and organic extract are combined, rinsed with aqueous sodium hydroxide (1N), brine, 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 (350 mg, 69% yield) as a colorless oil; cis/trans/1-2+1-4 addition, 92.7/6.3/1.0.

Source