921600-20-6

Basic information

• Product Name: 2,2-Azetidinedicarboxylic acid, 1-[(1S)-1-phenylethyl]-, 2,2-dimethyl ester
• CAS NO: 921600-20-6
• Molecular Formula: C15H19NO4
• Molecular Weight: 277.32
• Mol File: 921600-20-6.mol
• Article Data: 1

Chemical Properties

• CAS DataBase Reference: 2,2-Azetidinedicarboxylic acid, 1-[(1S)-1-phenylethyl]-, 2,2-dimethyl ester(CAS DataBase Reference)
• NIST Chemistry Reference: 2,2-Azetidinedicarboxylic acid, 1-[(1S)-1-phenylethyl]-, 2,2-dimethyl ester(921600-20-6)
• EPA Substance Registry System: 2,2-Azetidinedicarboxylic acid, 1-[(1S)-1-phenylethyl]-, 2,2-dimethyl ester(921600-20-6)

Safety Data

• Hazardous Substances Data: 921600-20-6(Hazardous Substances Data)

Upstream product

• 921600-22-8 dimethyl (1'S)-(1'-methyl)benzylaminomalonate 
• 106-93-4 ethylene dibromide 

Downstream Products

• 204274-30-6 methyl (2R,1'S)-1-(1'-methyl)benzylazetidine-2-carboxylate 
• 204274-29-3 methyl (2S,1'S)-1-(1'-methyl)benzylazetidine-2-carboxylate 
• 204274-33-9 (2S,1'S)-1-(1'-methyl)benzylazetidine-2-carboxylic acid 
• 210883-78-6 (2R,1'S)-1-(1'-methyl)benzylazetidine-2-carboxylic acid 
• 2133-34-8 (2S)-azetidine-2-carboxylic acid 

Relevant articles and documents

Efficient route to (S)-azetidine-2-carboxylic acid

A new and efficient route to (S)-azetidine-2-carboxylic acid (>99.9% ee) in five steps and total yield of 48% via malonic ester intermediates was established. As the key step, efficient four-membered ring formation (99%) was achieved from dimethyl (S)-(1′-methyl)benzylaminomalonate by treating with 1,2-dibromoethane (1.5 eq) and cesium carbonate (2 eq) in DMF. Krapcho dealkoxycarbonylation of dimethyl (1′S)-1-(1′-methyl) benzylazetidine-2,2-dicarboxylate, the product of this cyclization procedure, proceeded with preferential formation (2.7:1, 78% total yield) of the desired (2S,1′S)-monoester, with the help of a chiral auxiliary which was introduced on the nitrogen atom. The undesired (2R,1′S)-isomer could be converted to that with proper stereochemistry, by a deprotonation and subsequent reprotonation step. Finally, lipase-catalyzed preferential hydrolysis of the (2S,1′S)-monoester and subsequent deprotection provided enantiomerically pure (S)-azetidine-2-carboxylic acid in a 91% yield from the mixture of (2S,1′S)- and (2R,1′S)-isomers.