Reaction #2636

Reaction equation

tert-butyl methyl ether

lithium aluminum hydride

4-tert-butyldimethylsiloxy-2-cyclopentenone

lithium iodide

→

title compound

Yield 68.0%

cis-4-tert-butyldimethylsilyloxy-2-cyclopentenol

Yield 68.0%

Solvents

toluene

Conditions

Workup

1. 1
   Otherthe temperature of the reaction at or
2. 2
   workup.ADDITIONbelow -15° C. (total addition time is approximately 3 minutes)
3. 3
   workup.STIRRINGThe reaction is stirred for 3 hours at -20° C.
4. 4
   Otherit is quenched by slow addition of aqueous sodium hydroxide (1N, 250 mL) at a rate
5. 5
   Otherthe temperature of the reaction below 20° C
6. 6
   FiltrationThe resulting suspension is then filtered through a pad of diatomaceous earth
7. 7
   Washthe pad is subsequently rinsed with toluene (400 mL)
8. 8
   OtherThe filtrate phases are separated
9. 9
   Extractionthe aqueous phase is extracted with toluene (450 mL)
10. 10
    ExtractionThe organic phase and organic extract
11. 11
    Washrinsed with aqueous sodium hydroxide (1N, 450 mL), brine (450 mL)
12. 12
    Dryingdried over anhydrous magnesium sulfate
13. 13
    Filtrationfiltered
14. 14
    Concentrationconcentrated under vacuum (40° C., 20 mmHg)
15. 15
    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 (175 g, 824 mmol) in anhydrous toluene (1.5L) under an atmosphere of argon is treated with lithium iodide (240 g, 1.79 mol). The mixture is cooled to -20° C. and treated with lithium aluminum hydride (13.5 g, 356 mmol) in one portion. The reaction is then stirred for 5 minutes and anhydrous tert-butyl methyl ether (300 mL) is added at a rate that maintains the temperature of the reaction at or below -15° C. (total addition time is approximately 3 minutes). The reaction is stirred for 3 hours at -20° C. and then it is quenched by slow addition of aqueous sodium hydroxide (1N, 250 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 (400 mL). The filtrate phases are separated and the aqueous phase is extracted with toluene (450 mL). The organic phase and organic extract are combined, rinsed with aqueous sodium hydroxide (1N, 450 mL), brine (450 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 (120 g, 68% yield) as a colorless oil; cis/trans/1-2 +1-4 addition, 92/4/4.

Source