Reaktion #322973

Reaktionsgleichung

sucrose

γ-chloroacetoacetic octyl ester

sucrose

→

4-chloro-3(R)-hydroxybutyric acid octyl ester

Ausbeute 69.4%

Lösungsmittel

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.WAITto proceed for another 24 hours
2. 2
   SonstigeThe cells were then removed by filtration through a pad of celite
3. 3
   WaschenThe cells were washed with water and ethyl acetate
4. 4
   Extraktionexhaustively extracted with ethyl acetate
5. 5
   TrocknenThe ethyl acetate layer was dried over MgSO4
6. 6
   Sonstigeevaporated
7. 7
   Sonstigeto give an oily residue, which
8. 8
   Sonstigewas chromatographed over a silica gel column

Vorschrift

One hundred grams of commercial fresh Baker's yeast Saccharomyces cerevisiae (Red Star) was suspended in 250 ml of tap water to which was added 10 g of sucrose and 3.6 g of γ-chloroacetoacetic octyl ester. After the contents were incubated at 25° C. on a rotary shaker (250 cycles/minute--2" radius) for 24 hours, an additional 10 g of sucrose was added to the flask and the reaction was allowed to proceed for another 24 hours. The cells were then removed by filtration through a pad of celite. The cells were washed with water and ethyl acetate. The washings were combined with the filtrate and exhaustively extracted with ethyl acetate. The ethyl acetate layer was dried over MgSO4 and evaporated to give an oily residue, which was chromatographed over a silica gel column to yield 2.52 g of 4-chloro-3(R)-hydroxybutyric acid octyl ester, as a low melting solid; [α]D23 +13.2° (c, 4.0, CHCl3).

Quelle