Reaction #9331

Reaction equation

H2O2

L-selectride

ketone

(Z)-7-((1R,2S,3R)-3-(tert-Butyl-dimethyl-silanyloxy)-2-{4-[(tert-butyl-dimethyl-silanyloxy)-cyclohexyl-methyl]-phenyl}-5-oxo-cyclopentyl)-hept-5-enoic acid methyl ester

THF

NH4Cl

(Z)-7-((1R,2S,3R,5S)-3-(tert-Butyl-dimethyl-silanyloxy)-2-{4-[(tert-butyl-dimethyl-silanyloxy)-cyclohexyl-methyl]-phenyl}-5-hydroxy-cyclopentyl)-hept-5-enoic acid methyl ester

→

alcohol

Yield 93.0%

(Z)-7-((1R,2S,3R)-3-Hydroxy-2-{3-[hydroxy-(1-propyl-cyclobutyl)-methyl]-phenyl}-5-oxo-cyclopentyl)-hept-5-enoic acid ethyl amide

Yield 93.0%

Conditions

Workup

1. 1
   workup.STIRRINGThe reaction was stirred for 2 h at room temperature
2. 2
   ExtractionThe mixture was extracted with ethyl acetate (3×50 mL)
3. 3
   Washthe combined ethyl acetate solution was washed with brine
4. 4
   Dryingwas dried (Na2SO4)
5. 5
   Filtrationfiltered
6. 6
   Otherevaporated
7. 7
   OtherPurification by flash chromatography on silica gel (8% ethyl acetate/hexanes)

Procedure

Representative procedure for reduction of the C9 ketone: (Z)-7-((1R,2S,3R,5S)-3-(tert-Butyl-dimethyl-silanyloxy)-2-{4-[(tert-butyl-dimethyl-silanyloxy)-cyclohexyl-methyl]-phenyl}-5-hydroxy-cyclopentyl)-hept-5-enoic acid methyl ester (6-1). L-selectride (300 μL, 0.3 mmol, 1 M/THF) was added to a −78° C. solution of ketone 5-3 (159 mg, 0.24 mmol) in 12 mL THF. The reaction was stirred for 30 min. at −78° C. and then 3% H2O2 (7 mL) was added. The reaction was stirred for 2 h at room temperature and then was poured into saturated NH4Cl solution. The mixture was extracted with ethyl acetate (3×50 mL) and the combined ethyl acetate solution was washed with brine and then was dried (Na2SO4), filtered and evaporated. Purification by flash chromatography on silica gel (8% ethyl acetate/hexanes) gave the title alcohol (149 mg, 93%).

Source