341554-40-3

Upstream product

• 341554-38-9 (2R,3S)-3-Acetoxy-2-bromo-butyric acid 
• 161906-03-2 (2R,3S)-3-acetoxy-2-bromobutyryl chloride 
• 341554-39-0 dimethyl {N-[(2R,3S)-3-acetoxy-2-bromobutyryl]-N-(4-methoxyphenyl)aminomalonate} 

Downstream Products

• 341554-41-4 (αS,3S)-3-(1-acetoxyethyl)-2-methoxycarbonyl-1-(4-methoxyphenyl)-4-oxoazetidin-2-carboxylic acid 
• 341554-43-6 methyl [(αS,2R,3S)-3-(1-acetoxyethyl)-1-(4-methoxyphenyl)-4-oxoazetidin-2-carboxylate] 
• 341554-42-5 methyl [(αS,2SR,3S)-3-(1-acetoxyethyl)-1-(4-methoxyphenyl)-4-oxoazetidin-2-carboxylate] 
• 341554-44-7 (αS,3S,4S)-3-(1-acetoxyethyl)-4-hydroxymethyl-N-(4-methoxyphenyl)-azetidin-2-one 

Relevant academic research and scientific papers

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.