反応 #322973

反応方程式

sucrose

γ-chloroacetoacetic octyl ester

sucrose

→

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

収率 69.4%

溶媒

water

反応条件

後処理

1. 1
   workup.WAITto proceed for another 24 hours
2. 2
   その他The cells were then removed by filtration through a pad of celite
3. 3
   洗浄The cells were washed with water and ethyl acetate
4. 4
   抽出exhaustively extracted with ethyl acetate
5. 5
   乾燥The ethyl acetate layer was dried over MgSO4
6. 6
   その他evaporated
7. 7
   その他to give an oily residue, which
8. 8
   その他was chromatographed over a silica gel column

実験手順

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).

出典