96725-02-9

Upstream product

• 6506-31-6 dimethyl acetonedicarboxylate ethylene ketal 
• 1830-54-2 3-oxopentanedioic acid dimethyl ester 

Downstream Products

• 101834-22-4 methyl 4-<1-(benzyloxy)-2-oxo-3(S)-ethyl-4(R)-azetidinyl>-β,β-(ethylenedioxy)butyrate 
• 101834-21-3 [2-((2S,3R)-3-Benzyloxycarbamoyl-2-hydroxy-pentyl)-[1,3]dioxolan-2-yl]-acetic acid methyl ester 
• 96725-06-3 [2-((2S,3R)-3-Benzyloxycarbamoyl-2-methanesulfonyloxy-pentyl)-[1,3]dioxolan-2-yl]-acetic acid methyl ester 
• 96725-04-1 [2-((2S,3R)-3-Benzyloxycarbamoyl-2-hydroxy-pentyl)-[1,3]dioxolan-2-yl]-acetic acid methyl ester 
• 96725-05-2 [2-((2R,3R)-1-Benzyloxy-3-ethyl-4-oxo-azetidin-2-ylmethyl)-[1,3]dioxolan-2-yl]-acetic acid methyl ester 

Relevant academic research and scientific papers

Process for intermediates to 1-carbapenems and 1-carbacephems

A stereoselective process for chiral intermediates to 1-carbapenum and 1-carbacephalosporins is provided comprising the use of an N-acyl-(4R)-substituted-1,3-thiazolidine-2-thione as a chiral auxiliary in boron enolate mediated aldol condensation with a protected-β-keto ester aldehyde. E.g., benzyl 3,3-(ethylenedioxy)-4-formylbutyrate is condensed with the boron enolate formed with n-butyryl (4R)-methoxycarbonyl-1,3-thiazolidine-2-thione to provide benzyl 3,3-ethylenedioxy-(5R)-hydroxy-6-[(4R)-methoxycarbonyl-1,3-thiazolidine-2-thione-3-ylcarbonyl]octanoate. Displacement of the thiazolidine-2-thione chiral auxiliary moiety with an O-alkyl, O-acyl or O-aralkyl hydroxyamine provides the corresponding chiral intermediate as the hydroxamate.

THE APPLICATION OF HIGHLY STEREOSELECTIVE ALDOL CONDENSATIONS TO THE SYNTHESIS OF β-LACTAM ANTIBIOTICS.

Stereoselective aldol condensations of fully protected glycine and 3-butyryl thiazolidine-2-thiones with achiral aldehydes afforded β-hydroxyesters suitable for elaboration to key intermediates for the synthesis of β-lactam antibiotics.