Реакция #2356521

Уравнение реакции

n-butyllithium

diisopropylamine

cinnamyl bromide

methyl (3R)-3-hydroxybutanoate

→

methyl (2R,3R)-2-[(2E)-3-phenyl-2-propen-1-yl]-3-hydroxybutanoate

Выход 85.0%

Растворители

THF

HMPA

Условия реакции

Обработка

1. 1
   ТемператураThe reaction mixture is cooled to −78° C.
2. 2
   Температураto warm to 0° C.
3. 3
   workup.STIRRINGstirred for 16 h
4. 4
   ДругоеThe reaction mixture is quenched by addition 30 mL of saturated aqueous ammonium chloride solution
5. 5
   workup.ADDITIONis poured into 400 mL of 1 N hydrochloric acid
6. 6
   Экстракцияis extracted with two 500-mL portions of EtOAc
7. 7
   СушкаThe combined organic layers are dried over magnesium sulfate
8. 8
   Концентрированиеconcentrated in vacuo
9. 9
   Другоеpurified by silica gel chromatography (elution with 25% EtOAc-hexanes)

Методика

To a solution of diisopropylamine (47.1 g, 466.1 mmol) in THF (500 mL) cooled to −50° C. is added n-butyllithium (466.1 mmol, 2.5M in hexanes) and the resulting solution is stirred at −50° C. for 0.5 h. The reaction mixture is cooled to −78° C. followed by slow addition of methyl (3R)-3-hydroxybutanoate (25 g, 211.9 mmol). After 0.5 h a solution of cinnamyl bromide (45.9 g, 233.0 mmol) in HMPA (10 mL) is added and the reaction mixture is allowed to warm to 0° C. and stirred for 16 h. The reaction mixture is quenched by addition 30 mL of saturated aqueous ammonium chloride solution, is poured into 400 mL of 1 N hydrochloric acid, and is extracted with two 500-mL portions of EtOAc. The combined organic layers are dried over magnesium sulfate, concentrated in vacuo, and purified by silica gel chromatography (elution with 25% EtOAc-hexanes) to afford methyl (2R,3R)-2-[(2E)-3-phenyl-2-propen-1-yl]-3-hydroxybutanoate as a yellow oil (42 g, 85% yield).

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