Reaktion #978021

Reaktionsgleichung

(S)-6-benzoyloxy-3-oxo-5-hydroxyhexanoic acid tert-butylester

(S)-6-benzoyloxy-3-oxo-5-hydroxyhexanoic acid tert-butylester

Hydrogen

→

(3S, 5S)-6-benzoyloxy-3,5-dihydroxyhexanoic acid tert-butylester

Ausbeute 82.3%

Lösungsmittel

methanol water

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigeat −78° C.
2. 2
   Sonstigeto react for twenty hours under a hydrogen pressure of 5.0 kg/cm2
3. 3
   ExtraktionAfter extraction of hydrogen
4. 4
   Sonstigecondensed
5. 5
   Sonstigepurified by silica gel column chromatography

Vorschrift

To (S)-6-benzoyloxy-3-oxo-5-hydroxyhexanoic acid tert-butylester (161 mg, 0.50 mmol) and RuBr2(S)-BINAP (4.4 mg, 0.0050 mmol) (BINAP was 2,2′-bisdiphenylphosphino-1,1′-binaphthyl), 2 mL of a methanol-water (10/1) solution was added to completely dissolve the (S)-6-benzoyloxy-3-oxo-5-hydroxyhexanoic acid tert-butylester and RuBr2(S)-BINAP in an argon atmosphere. Hydrogen replacement at −78° C. was performed three times. After the temperature of the resulting mixture had increased to 50° C., the mixture was allowed to react for twenty hours under a hydrogen pressure of 5.0 kg/cm2. After extraction of hydrogen, the mixture was condensed and purified by silica gel column chromatography. As a result, 133.4 mg (82%) of (3S, 5S)-6-benzoyloxy-3,5-dihydroxyhexanoic acid tert-butylester was obtained. The diastereomer ratio determined by high performance liquid chromatography (HPLC) analysis was (3R, 5S):(3S, 5S)=10.4/89.6.

Quelle