반응 #58771

반응 방정식

2-oxobutyric acid

(−)-8-phenylmenthol

→

title compound

수율 92.5%

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

수율 92.5%

용매

benzene

반응 조건

후처리

1. 1
   온도to reflux for 20 h 35 min
2. 2
   세척the solution was washed twice with 50 mL saturated aqueous sodium hydrogencarbonate solution
3. 3
   건조The organic phase was dried over 5 g sodium sulfate
4. 4
   여과was filtered
5. 5
   세척The filter cake was washed with 10 mL benzene
6. 6
   기타The organic phase was evaporated to dryness in a rotary evaporator (40° C., 20 mbar)

실험 절차

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.

출처