prop-2-enyl 2-chloro-2-oxoacetate

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

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

Conditions: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

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

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: By the procedure of the preceding Preparation, allyl oxalochloride (252.5 g, 1.70 mol) and cesium fluoride (284 g, 1.87 mol) were converted to twice distilled title product, b.p. 48°-50° C./35 mm; 124°-126° C. (atmospheric pressure). to twice distilled title product, b.p. 48°-50° C./35 mm 124°-126° C. (atmospheric pressure)

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: By the procedure of the preceding Preparation, allyl oxalochloride (252.5 g, 1.70 mol) and cesium fluoride (284 g, 1.87 mol) were converted to twice distilled title product, b.p. 48°-50° C./35 mm; 124°-126° C. (atmospheric pressure). to twice distilled title product, b.p. 48°-50° C./35 mm 124°-126° C. (atmospheric pressure)

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: By the procedure of the preceding Preparation, allyl oxalochloride (252.5 g, 1.70 mol) and cesium fluoride (284 g, 1.87 mol) were converted to twice distilled title product, b.p. 48°-50° C./35 mm; 124°-126° C. (atmospheric pressure). to twice distilled title product, b.p. 48°-50° C./35 mm 124°-126° C. (atmospheric pressure)

Conditions: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

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

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: In dichloromethane (2.5 ml) was dissolved the (3S,4R)-3-[(R)-1-(allyloxycarbonyloxy)ethyl]-4-[(1S)-3-[2-(tert-butyldimethylsilyloxy)ethyl]-2-oxocyclohexan-1-yl]azetidin-2-one (0.56 g) obtained in Reference Example 3 and while the solution was stirred, a solution of triethylamine (0.7 ml) in dichloromethane (2.5 ml) was added. Then, a solution of allyloxyoxalyl chloride (0.55 g) in dichloromethane (2.5 ml) was added dropwise at -78° C. over a period of 10 minutes. The reaction mixture was stirred at -78° C. for 5 minutes and, then, at 0° C. for 3 hours. The reaction mixture was diluted with ethyl acetate, washed with phosphate buffer (pH 7) and aqueous sodium chloride in that order and, after addition of triethylamine (0.2 ml), dried over anhydrous sodium sulfate. The solvent was then distilled off under reduced pressure and the residue was purified by flash column chromatography (stationary phase: silica gel 15 g; ethyl acetate-hexane 1:6) to give allyl [(3S,4R)-3-[(R)-1-(allyloxycarbonyloxy)ethyl]-4-[(1S)-3-[2-(tert-butyldimethylsilyloxy)ethyl]-2-oxocyclohexan-1-yl]-2-oxoazetidin-1-yl]glyoxylate. obtained in Reference Example 3 and while the solution The reaction mixture was stirred at -78° C. for 5 minutes washed with phosphate buffer (pH 7) and aqueous sodium chloride in that order after addition of triethylamine (0.2 ml) dried over anhydrous sodium sulfate The solvent was then distilled off under reduced pressure the residue was purified by flash column chromatography (stationary phase: silica gel 15 g; ethyl acetate-hexane 1:6)