Reaction #2640

Reaction equation

tert-butyl methyl ether

4-tert-butyldimethylsiloxy-2-cyclopentenone

MgBr2

lithium aluminum hydride

lithium aluminum hydride

→

title compound

Yield 64.4%

cis-4-tert-butyldimethylsilyloxy-2-cyclopentenol

Yield 64.4%

Solvents

toluene

Conditions

Workup

1. 1
   Otherovernight
2. 2
   Otherat room temperature
3. 3
   workup.STIRRINGthe reaction is stirred for 2 hours
4. 4
   OtherThe reaction is then quenched by slow addition of 1N NaOH (5 mL)
5. 5
   Filtrationfollowed by filtration through diatomaceous earth
6. 6
   DryingThe filtrate is dried over anhydrous magnesium sulfate
7. 7
   Filtrationfiltered
8. 8
   Concentrationconcentrated under vacuum

Procedure

A stirred solution of 4-tert-butyldimethylsiloxy-2-cyclopentenone (2.0 g, 9.42 mmol) in anhydrous toluene (15 mL) under an atmosphere of argon is treated with MgBr2 (3.5 g, 19.0 mol). The mixture is cooled to -25° C. and treated with lithium aluminum hydride (178 mg, 4.69 mmol) in one portion, followed by addition of anhydrous tert-butyl methyl ether (3.0 mL). The reaction is stirred at -20° C. for 2 hours and then overnight at room temperature. Additional lithium aluminum hydride (178 mg, 4.69 mmol) is added at room temperature and the reaction is stirred for 2 hours. The reaction is then quenched by slow addition of 1N NaOH (5 mL) followed by filtration through diatomaceous earth. The filtrate is dried over anhydrous magnesium sulfate, filtered and concentrated under vacuum to provide the title compound (1.3 g); cis/trans/1-2 +1-4 addition, 90/3/7.

Source