Reaction #1857551

Reaction equation

(S)-methyl 2-((S)-1-((4-methoxybenzyl)oxy)ethyl)-5-methylhexanoate

→

(S)-2-((S)-1-((4-methoxybenzyl)oxy)ethyl)-5-methylhexanal

Solvents

DCM

Conditions

Workup

1. 1
   Otherat 0° C
2. 2
   OtherThe flask was removed from the cold bath
3. 3
   Temperaturecooled
4. 4
   workup.ADDITIONmixture of diethyl ether (Et2O; 60 mL) and 2 Normal (N) HCl (20 mL) over 15 min
5. 5
   OtherThe mixture was removed from the cold bath
6. 6
   workup.STIRRINGstirred at room temperature for 30 min
7. 7
   OtherThe phases were separated
8. 8
   Extractionthe aq. phase was further extracted with Et2O (2×50 mL)
9. 9
   Washwashed with sat. aq. sodium bicarbonate (NaHCO3; 25 mL) and brine (25 mL)
10. 10
    Dryingdried over Na2SO4
11. 11
    Filtrationfiltered
12. 12
    workup.ADDITIONthe filtrate treated with Celite® (5 scoopula tip-fulls)
13. 13
    OtherThe solvent was removed under reduced pressure
14. 14
    Otherpurified

Procedure

To a solution of (S)-methyl 2-((S)-1-((4-methoxybenzyl)oxy)ethyl)-5-methylhexanoate (6.00 g, 19.5 mmol) and chlorobis(cyclooctene)-iridium(I) dimer (0.349 g, 0.389 mmol) in dry DCM (19.5 mL) was slowly added Et2SiH (3.76 mL, 29.2 mmol) at 0° C. The flask was removed from the cold bath and the reaction was stirred at room temperature for 20 h under nitrogen (N2). The reaction mixture was transferred via cannula to an ice-cooled mixture of diethyl ether (Et2O; 60 mL) and 2 Normal (N) HCl (20 mL) over 15 min. The mixture was removed from the cold bath and stirred at room temperature for 30 min. The phases were separated and the aq. phase was further extracted with Et2O (2×50 mL). The organics were combined, washed with sat. aq. sodium bicarbonate (NaHCO3; 25 mL) and brine (25 mL), dried over Na2SO4, filtered, and the filtrate treated with Celite® (5 scoopula tip-fulls). The solvent was removed under reduced pressure and the resulting adsorbed material was directly loaded onto a column and purified using flash column chromatography (120 g SiO2, 0→75% EtOAc/hexanes) to afford the intermediate aldehyde, (S)-2-((S)-1-((4-methoxybenzyl)oxy)ethyl)-5-methylhexanal.

Source