Reaktion #48542

Reaktionsgleichung

sodium bis(trimethylsilyl)amide

(2R,4S)-2-tert-butyl-3-formyloxazolidine-4-carboxylic acid methyl ester

1-iodobutane

HMPA

→

title compound

Ausbeute 69.0%

(2R,4S)-4-Butyl-2-tert-butyl-3-formyloxazolidine-4-carboxylic acid methyl ester

Ausbeute 69.0%

Lösungsmittel

THF

ether

THF

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturthe reaction mixture was warmed to 0° C.
2. 2
   Sonstigequenched with saturated aqueous NH4Cl (200 mL)
3. 3
   SonstigeThe quenched reaction mixture
4. 4
   Waschenwashed with water (3×200 mL) and brine (200 mL)
5. 5
   Trocknendried (Na2SO4)
6. 6
   Filtrationfiltered

Vorschrift

To a solution of (2R,4S)-2-tert-butyl-3-formyloxazolidine-4-carboxylic acid methyl ester (4.6 g, 21.4 mmol) [see D. Seebach, J. D. Aebi, M. Gander-Coquoz and R. Naef, Helv. Chim. Acta., 70, 1194 (1987)] in dry THF (120 mL) under N2 was added 1-iodobutane (12.2 mL, 106.8 mmol) and HMPA (12 mL). The mixture was cooled to −78° C. and a solution of sodium bis(trimethylsilyl)amide in THF (1 M, 32 mL, 32 mmol) was added dropwise over 15 minutes. After 2 h, the reaction mixture was warmed to 0° C. and quenched with saturated aqueous NH4Cl (200 mL). The quenched reaction mixture was diluted with ether (400 mL) and washed with water (3×200 mL) and brine (200 mL), then dried (Na2SO4) and filtered. Concentration of the filtrate and flash chromatography of the residue (20% ethyl acetate/hexanes) provided the title compound as a pale brown solid (4.0 g, 69%). MS(ES) m/e 272 [M+H]+.

Quelle