反応 #58771

反応方程式

2-oxobutyric acid

(−)-8-phenylmenthol

→

title compound

収率 92.5%

2-oxo-butyric acid (1R,2S,5R)-5-methyl-2-(1-methyl-1-phenyl-ethyl)-cyclohexyl ester

収率 92.5%

溶媒

benzene

反応条件

後処理

1. 1
   温度to reflux for 20 h 35 min
2. 2
   洗浄the solution was washed twice with 50 mL saturated aqueous sodium hydrogencarbonate solution
3. 3
   乾燥The organic phase was dried over 5 g sodium sulfate
4. 4
   ろ過was filtered
5. 5
   洗浄The filter cake was washed with 10 mL benzene
6. 6
   その他The organic phase was evaporated to dryness in a rotary evaporator (40° C., 20 mbar)

実験手順

A solution of 2.28 g 2-oxobutyric acid (2, 22.11 mmol, 1.3 eq), 4.04 g (−)-8-phenylmenthol (18, 17.02 mmol, 1.0 eq) and 169.9 mg para-toluenesulfonic acid monohydrate (0.884 mmol, 0.52 eq) in 48 mL benzene was heated to reflux for 20 h 35 min. After cooling down to room temperature, the solution was washed twice with 50 mL saturated aqueous sodium hydrogencarbonate solution, and subsequently with 50 mL water and 50 mL brine. The organic phase was dried over 5 g sodium sulfate and was filtered. The filter cake was washed with 10 mL benzene. The organic phase was evaporated to dryness in a rotary evaporator (40° C., 20 mbar) yielding the title compound (4.98 g, 92% by weight) as colorless solid.

出典