Triethylamine → HCID 86749052, compound

Participants

Reaction Steps

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.

Provenance & Evidence