Reaktion #2182710

Reaktionsgleichung

natriumborohydrid

Z-Glu(OtBu)-OH

4-methylmorpholine

ethyl chloroformate

KHSO4

→

titled compound

(S)-4-Benzyloxycarbonylamino-5-hydroxy-pentanoic acid tert-butyl ester

Lösungsmittel

Methanol

THF

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeKokotos (Synthesis 1990, 299)
2. 2
   SonstigeThe organic solvents are evaporated under reduced pressure
3. 3
   workup.ADDITIONthe obtained residue is poured on a 10% KHSO4
4. 4
   Extraktionextracted with EtOAc (3×)
5. 5
   WaschenThe organic phases were washed with aqueous 10% KHSO4, 10% NaCl
6. 6
   Trocknendried over Na2SO4
7. 7
   Sonstigeevaporated

Vorschrift

In analogy to G. Kokotos (Synthesis 1990, 299), a solution of 5.00 g (14.8 mmol) of Z-Glu(OtBu)-OH in 74.0 ml of THF was treated at −10° C. with 1.63 ml (14.8 mmol) of 4-methylmorpholine, 1.41 ml (14.8 mmol) of ethyl chloroformate. After 10 min 1.682 g (44.5 mmol) of natriumborohydrid was added in one portion. Methanol (148 ml) was then added dropwise over a period of 25 min at 0° C. The solution was stirred 20 min, and then neutralized with a 10% KHSO4 solution. The organic solvents are evaporated under reduced pressure and the obtained residue is poured on a 10% KHSO4 extracted with EtOAc (3×). The organic phases were washed with aqueous 10% KHSO4, 10% NaCl, dried over Na2SO4 and evaporated to yield 5.16 g (quantitative) of the titled compound as yellow oil. MS: 324.18 (MH+).

Quelle