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 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).

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 N hydrochloric acid
6. extractionis extracted with two 500-mL portions of EtOAc
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% EtOAc-hexanes)

ORD record

ord-d969249243d24593a6ba6d50d817b8c3

Source dataset

uspto-grants-2001_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06329400B1