N-(tert-Butoxycarbonyl)-D-prolinal → tert-Butyl (2R)-2-ethenylpyrrolidine-1-carboxylate

Temperatur

-78 °C

n-Butyl lithium (1.6 M in hexanes)(27 mL, 43 mmol) was added to ice-cold hexamethyldisilazane (9.2 mL, 44 mmol) under a nitrogen atmosphere. The solution was stirred for 10 min and was then added to a suspension of methyl(triphenylphosphonium)bromide (15.5 g, 43 mmol) in 100 mL of THF at ambient temperature. After stirring for 1 h, the mixture was cooled to −78° C. and a solution of tert-butyl (2R)-2-formylpyrrolidine-1-carboxylate (7.9 g, 40 mmol) in 50 mL of THF was added. The cold bath was removed and the mixture stirred overnight at ambient temperature. The reaction mixture was then quenched with saturated NH4Cl, the phases were separated, and the organic phase was washed with saturated NH4Cl, brine, dried over Na2SO4, filtered, and concentrated to give an orange oil. The oil was purified on a Biotage 40M column eluting with heptane to give tert-butyl (2R)-2-vinylpyrrolidine-1-carboxylate (5.0 g).

1. stirringAfter stirring for 1 h
2. customThe cold bath was removed
3. stirringthe mixture stirred overnight at ambient temperature
4. customThe reaction mixture was then quenched with saturated NH4Cl
5. customthe phases were separated
6. washthe organic phase was washed with saturated NH4Cl, brine
7. dry with materialdried over Na2SO4
8. filtrationfiltered
9. concentrationconcentrated
10. customto give an orange oil
11. customThe oil was purified on a Biotage 40M column
12. washeluting with heptane

ORD-Eintrag

ord-5a252afea5304c66a4216a1c5cfd2a47

Quelldatensatz

uspto-grants-2010_06

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US07727997B2