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• 74694-48-7 4(S)-4-hydroxymethyl azetidin-2-one 
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Relevant academic research and scientific papers

Simple and Condensed &β-Lactams, XIX. - Synthesis of Some New 7-Acylamino-2-iso-oxacephem-4-carboxylic Acids

General methods have been developed for the synthesis of 7-amino-2-iso-oxacephem-4-carboxylic acid esters 21a, b; 35b.Clayfen was used for the preparation of benzyl 2,3-dioxobutyrate (3).The latter readily reacted with N(1)-unsubstituted β-lactams (9a, 28) to give products formed by addition reaction on the middle carbonyl-C atom.These intermediates furnished the corresponding acetoacetic esters 10, 29 which gave by ring closure the O-mono- and the O,N-diprotected-2-iso-oxacephems (11, 30).Intermolecular carbene insertion was used for the synthesis of tert-butyl 2-(2-oxoazetidin-1-yl)acetoacetates 19a, b whose ring closure led to the tert-butyl 2-iso-oxacephem-4-carboxylates 20a, b.The O-protecting tert-butyl group could be removed without decomposition of the 2-isooxacephem moiety to give 2-iso-oxacephem-4-carboxylic acids 2a, b which exhibit antibacterial activity against Grampositive microorganisms. - Key Words: Benzyl 2,3-dioxobutyrate / 2-Iso-oxacephems / Antibacterial activity

Simple and Condensed β-Lactams 12. Alternative Entry into the 2-Isocephem and 2-Iso-oxacephem Series.

The N-Unsubstituted-2-azetidinones ( 17a,b) react smoothly with esters of 2,3-dioxobutyric acid.In resulting intermediates (29b; 30a,b) were converted into the acetoacetates (33b; 34a,b) which were cyclized and deprotected to give the 2-iso-oxacephem- and 2-isocephem-4-carboxylic acids (1a,b) and (2a,b).

Synthesis of 7-Oxo-3-oxa-1-azabicycloheptane-2-carboxylates: Analogues of Clavulanic Acid

4-Iodomethylazetidin-2-one is converted into the title compounds when treated sequentially with glyoxylic acid esters and sodium hydride.