Acetic Acid → methyl 2-[(3R,4R)-3-(1-hydroxy-1-methylethyl)-3-isocyano-2-oxo-4-allylazetidin-1-yl]-3-methylbut-2-enoate

Temperatur

-78 °C

To a solution of methyl 2-[(3R,4R)-3-isocyano-2-oxo-4-allylazetidin-1-yl]-3-methylbut-2-enoate (106.9 mg) in tetrahydrofuran (2.1 ml) was added dropwise a solution of n-butyl lithium (0.375 ml of 1.38 M solution in hexane) at -78° C. After stirring for 15 minutes at -78° C., the reaction mixture was added with a solution of acetone (0.0385 ml) in tetrahydrofuran (0.3465 ml) at -78° C. After stirring for 25 minutes at -78° C., the reaction mixture was added with acetic acid (0.0493 ml) at -78° C., diluted with ethyl acetate (30 ml), and washed with chilled brine (10 ml), aqueous sodium bicarbonate (10 ml), brine (10 ml), and saturated aqueous sodium chloride (10 ml). After drying over magnesium sulfate, the ethyl acetate extract was filtered and evaporated in vacuo. The residual oil was chromatographed on silica gel (1.2 g) eluting with a mixture of ethyl acetate and hexane (1:5-1:3) to give methyl 2-[(3R,4R)-3-(1-hydroxy-1-methylethyl)-3-isocyano-2-oxo-4-allylazetidin-1-yl]-3-methylbut-2-enoate (96.5 mg) as an oil.

1. stirringAfter stirring for 25 minutes at -78° C.
2. washwashed with chilled brine (10 ml), aqueous sodium bicarbonate (10 ml), brine (10 ml), and saturated aqueous sodium chloride (10 ml)
3. dry with materialAfter drying over magnesium sulfate
4. extractionthe ethyl acetate extract
5. filtrationwas filtered
6. customevaporated in vacuo
7. customThe residual oil was chromatographed on silica gel (1.2 g)
8. washeluting with a mixture of ethyl acetate and hexane (1:5-1:3)

ORD-Eintrag

ord-5a4b113f27f54e3f98da1a2f9f3c363d

Quelldatensatz

uspto-grants-1983_05

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US04383945