Dimethylformamide → methyl N-[(pent-4-enyloxy)carbonyl]-norleucinate

To a solution of 1-penten-4-ol (0.95 g, 11.0 mmol) in DMF (15 mL) at 0° C. was added carbonyldiimidazole (1.79 g, 11.0 mmol). The reaction mixture was warmed to RT and stirred for 30 min. L-norleucine methyl ester hydrochloride (2.0 g, 1.0 mmol) was then added, the reaction mixture was heated to 50° C. and stirred for 15 min. Upon cooling, the reaction mixture was diluted with ethyl ether and washed twice with water. The organic layer was dried over NaSO4, filtered and concentrated. The crude product was purified by silica gel chromatography (gradient elution 10 to 90% ethyl acetate in hexanes) to afford [(4-pentenyloxy)carbonyl]-L-norleucine methyl ester (2.1 g, 74% yield) as a clear oil. 1H NMR (500 MHz, CDCl3) ppm: δ 5.81 (m, 1H), 5.14 (d, J=7.6 Hz, 1H), 5.06-4.97 (m, 2H), 4.35 (q, J=5.4 Hz, 1H), 4.08 (t, J=6.6 Hz, 2H), 3.75 (s, 3H), 2.12 (q, J=7.1 Hz, 2H), 1.82 (brs, 1H), 1.72 (quin, J=7.1 Hz, 2H), 1.65 (br s, 1H), 1.32 (m, 4H), 0.90 (t, J=7.1 Hz, 3H).

1. temperaturethe reaction mixture was heated to 50° C.
2. stirringstirred for 15 min
3. temperatureUpon cooling
4. washwashed twice with water
5. dry with materialThe organic layer was dried over NaSO4
6. filtrationfiltered
7. concentrationconcentrated
8. customThe crude product was purified by silica gel chromatography (gradient elution 10 to 90% ethyl acetate in hexanes)

ORD-Eintrag

ord-90c31b849ff34130b5ff503896788b69

Quelldatensatz

uspto-grants-2011_02

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US07879797B2