Reacción #362465

Ecuación de reacción

ethanol

(3S,4S)-3-[(R)-1-(trimethylsilyloxy)-ethyl]-4-[(R)-3-oxo-1,4-dithian-2-yl]azetidin-2-one

pyridine

allyl chloroglyoxylate

→

allyl [(3S,4S)-2-oxo-4-[ (R)-3-oxo-1,4-dithian-2-yl]-3-[(R)-1-(trimethylsilyloxy)ethyl]azetidin-1-yl]glyoxylate

Rendimiento 97.2%

Disolventes

ether

dichloromethane

dichloromethane

dichloromethane

Condiciones de reacción

Tratamiento posterior

1. 1
   workup.STIRRINGthe mixture was stirred for 10 minutes
2. 2
   LavadoThe organic layer was washed with water, saturated copper sulfate solution and saturated aqueous sodium chloride solution in the order
3. 3
   Secadodried over anhydrous magnesium sulfate
4. 4
   workup.DISTILLATIONThe solvent was then distilled off under reduced pressure
5. 5
   Otrothe residue was purified by flash column chromatography (packing: silica gel; ethyl acetate-hexane=1:5)

Procedimiento

A solution of (3S,4S)-3-[(R)-1-(trimethylsilyloxy)-ethyl]-4-[(R)-3-oxo-1,4-dithian-2-yl]azetidin-2-one (650 mg), prepared in Reference Example 14, in dichloromethane (10 ml) was cooled at 0° C. and a solution of pyridine (483 mg) in dichloromethane (2 ml) and a solution of allyl chloroglyoxylate (603 g) in dichloromethane (3 ml) were added. The mixture was stirred at the same temperature for 2 hours. To this mixture was added ethanol (187 mg) at 0° C. and the mixture was stirred for 10 minutes, after which ether (30 ml) was added. The organic layer was washed with water, saturated copper sulfate solution and saturated aqueous sodium chloride solution in the order mentioned and dried over anhydrous magnesium sulfate. The solvent was then distilled off under reduced pressure and the residue was purified by flash column chromatography (packing: silica gel; ethyl acetate-hexane=1:5). The procedure gave allyl [(3S,4S)-2-oxo-4-[ (R)-3-oxo-1,4-dithian-2-yl]-3-[(R)-1-(trimethylsilyloxy)ethyl]azetidin-1-yl]glyoxylate as a colorless oil (853 mg).

Fuente