Diisopropylamine → HCID 86633705, compound

Temperature

-50 °C

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 M hydrochloric acid, and is extracted with two 500 mL portions of ethyl acetate. The combined organic layers are dried over magnesium sulfate, concentrated in vacuo, and purified by silica gel chromatography (elution with 25% ethyl acetate-hexanes) to afford methyl (2R,3R)-2-[(2E)-3-phenyl-2-propen-1-yl]-3-hydroxybutanoate as a yellow oil (42 g, 85% yield).

1. temperatureThe reaction mixture is cooled to −78° C.
2. temperatureto warm to 0° C.
3. stirringstirred for 16 h
4. customThe reaction mixture is quenched by addition 30 mL of saturated aqueous ammonium chloride solution
5. additionis poured into 400 mL of 1 M hydrochloric acid
6. extractionis extracted with two 500 mL portions of ethyl acetate
7. dry with materialThe combined organic layers are dried over magnesium sulfate
8. concentrationconcentrated in vacuo
9. custompurified by silica gel chromatography (elution with 25% ethyl acetate-hexanes)

ORD record

ord-833e649a852941dcb3c7730fdc448ad6

Source dataset

uspto-grants-2001_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06172064B2