反応 #58772

反応方程式

tetrahydrofuran

compound ( 17 )

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

isopropenylmagnesium bromide

→

title compound

(2S)-2-ethyl-2-hydroxy-3-methyl-but-3-enoic acid (1R,2S,5R)-5-methyl-2-(1-methyl-1-phenyl-ethyl)-cyclohexyl ester

反応条件

後処理

1. 1
   workup.ADDITIONwere added dropwise at −78° C
2. 2
   その他the reaction mixture was quenched by addition of 110 mL saturated aqueous ammonium chloride solution
3. 3
   抽出was extracted twice with 110 mL ethyl acetate
4. 4
   洗浄The combined organic phases were washed with 110 mL brine
5. 5
   乾燥dried over 15 g sodium sulfate
6. 6
   ろ過were filtered
7. 7
   洗浄The filter cake was washed with 30 mL ethyl acetate
8. 8
   その他The organic phase was evaporated to dryness in a rotary evaporator (40° C., 8 mbar)

実験手順

To a solution of 4.200 g of compound (17) as obtained from example 11 (13.27 mmol) in 168 mL tetrahydrofuran were added dropwise at −78° C. 39.8 mL isopropenylmagnesium bromide (19.91 mmol, 1.5 eq). After additional 50 min, the reaction mixture was quenched by addition of 110 mL saturated aqueous ammonium chloride solution, and was extracted twice with 110 mL ethyl acetate. The combined organic phases were washed with 110 mL brine, dried over 15 g sodium sulfate and were filtered. The filter cake was washed with 30 mL ethyl acetate. The organic phase was evaporated to dryness in a rotary evaporator (40° C., 8 mbar) yielding the title compound (4.790 g, 101% by weight, dr=93:7)as a yellow oil.

出典