Reaktion #49170

Reaktionsgleichung

lithium borohydride

methyl ester

1-(6-Benzyloxycarbonylamino-hexanoyl)-4-hydroxy-pyrrolidine-2-carboxylic acid methyl ester

→

[6-(4-Hydroxy-2-hydroxymethyl-pyrrolidin-1-yl)-6-oxo-hexyl]-carbamic acid benzyl ester

Lösungsmittel

tetrahydrofuran

THF

MeOH CHCl3

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONAfter the addition the reaction mixture
2. 2
   Sonstigewas brought to room temperature
3. 3
   SonstigeThe reaction mixture was evaporated to dryness
4. 4
   workup.ADDITIONTo the residue 3N HCl (100 mL) was added slowly
5. 5
   Extraktionwas extracted with dichloromethane (3×100 mL)
6. 6
   WaschenThe combined organic layer was washed with brine
7. 7
   Trocknendried over sodium sulfate
8. 8
   FiltrationOrganic layer was filtered
9. 9
   Sonstigeevaporated to dryness
10. 10
    SonstigeCompound 3a was purified by column chromatography first
11. 11
    Waschenby eluting with ethyl acetate
12. 12
    Sonstigeto remove impurities
13. 13
    Sonstigegave 14.3 g (70%)

Vorschrift

To the solution of lithium borohydride (1.34 g) in anhydrous tetrahydrofuran (50 mL) was added a solution of methyl ester 2a in THF (50 mL) over a period of 30 mins at 0° C. After the addition the reaction mixture was brought to room temperature and stiired further under argon. The completion of the reaction was ascertained by TLC after 4 h. (Rf=0.4 in 10% MeOH/CHCl3). The reaction mixture was evaporated to dryness and cooled to 0° C. To the residue 3N HCl (100 mL) was added slowly. After stirring for 30 mins the product was extracted with dichloromethane (3×100 mL). The combined organic layer was washed with brine and dried over sodium sulfate. Organic layer was filtered and evaporated to dryness. Compound 3a was purified by column chromatography first by eluting with ethyl acetate to remove impurities followed by dichloromethane/methanol (5%) gave 14.3 g (70%).

Quelle