341554-31-2

Upstream product

• 35757-94-9 dimethyl [N-(4-methoxyphenyl)aminomalonate] 
• 112245-37-1 (2S,3R)-2-bromo-3-acetoxybutyroyl chloride 
• 171340-06-0 (2S,3R)-2-bromo-3-(ethanoyloxy)butanoic acid 

Downstream Products

• 341554-37-8 (αR,3R)-3-(1-acetoxyethyl)-2-methoxycarbonyl-1-(4-methoxyphenyl)-4-oxoazetidin-2-carboxylic acid 
• 341554-33-4 methyl [(αR,2RS,3R)-3-(1-acetoxyethyl)-1-(4-methoxyphenyl)-4-oxoazetidin-2-carboxylate] 
• 341554-34-5 methyl [(αR,2S,3R)-3-(1-acetoxyethyl)-1-(4-methoxyphenyl)-4-oxoazetidin-2-carboxylate] 
• 341554-36-7 (αR,3R,4R)-3-(1-acetoxyethyl)-4-hydroxymethyl-N-(4-methoxyphenyl)-azetidin-2-one 
• 341554-32-3 dimethyl [(αR,3R)-3-(1-acetoxyethyl)-1-(4-methoxyphenyl)-4-oxoazetidin-2,2-dicarboxylate] 

Relevant academic research and scientific papers

Stereocontrolled synthesis of methyl αR,2S,3R-3-(1-acetoxyethyl)-1-(4-methoxyphenyl)-4-oxoazetidine-2- carboxylate

A stereocontrolled synthesis of the key intermediates for 2-iso-oxa- and 2-isocephems is described. The absolute configuration of the title ester 8a is unambiguously determined by using X-ray analysis.

Synthesis of pure methyl [(2S,3R,αR)-1-(3-bromo-4-methoxyphenyl)-3-(α-acetoxy)ethyl-4- oxoazetidin-2-carboxylate] and its enantiomer

Synthesis of key intermediates leading to 2-iso-oxacephems was carried out starting from L- and D-threonine. As predicted in our previous paper (Tetrahedron Lett. 1995, 36, 8303-8306) all diastereomers of 2-iso-oxacephems can be prepared from the appropriate enantiomers of the amino acid threonine. The absolute configuration of the 2,3- and α-carbon atoms in the β-lactam structure was determined by X-ray crystallographic studies.