80951-80-0Relevant academic research and scientific papers
Carbapenams and carbapen-2-ems and process therefor
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, (2008/06/13)
Carbapenam-3-carboxylic acids and carbapen-2-em-3-carboxylic acids substituted at the 1-position with an oxo, a hydroxy or an acetoxy group, variously substituted at the 2-position with such groups as methyl, acetoxymethyl, methanesulfonyloxy, alkoxy, alkylthio, aminoalkylthio or amidinoalkylthio and optionally substituted at the 6-position with a hydroxyalkyl group, an acetoxyalkyl group or a conventional penicillin side-chain, pharmaceutically-acceptable salts thereof and various esters thereof wherein the esterifying group is selectively removed in the laboratory, or hydrolyzed under physiological conditions. These compounds are useful either systemically or topically in the treatment of diseases caused by susceptible microorganisms, as animal feed additives for promotion of growth, or in the preservation of biodegradable materials, or as intermediates to compounds having such antibacterial activity. Key to the synthesis of these compounds is the light catalyzed rearrangement of 2-diazo-1-oxoceph-3-em-4-carboxylates to 1-oxocarbapen-2-em-3-carboxylates, a newly discovered reaction determined to be of general applicability.
FROM PENICILLIN TO PENEM AND CARBAPENEM. II. SYNTHESIS OF 3,4-DISUBSTITUTED AZETIDINONE DERIVATIVES FROM 6,6-BIS(PHENYLSELENYL)PENICILLANATE
Hirai, Koichi,Iwano, Yuji,Fujimoto, Katsumi
, p. 4021 - 4024 (2007/10/02)
6,6-Bis(phenylselenyl)penicillanate 2a was converted into 6-1'-(R)-hydroxyethyl substituted penicillanate 5 in high yield.Compound 5 was deselenylated to 10.Oxidation, and then the basic epimerization of cis sulfone 11 gave trans sulfone derivative 12.The trans sulfone 12 was degraded to the monocyclic β-lactams 14, 15 which are important precursors for the carbapenem synthesis.
2-(Alkylthio)penem-3-carboxylic Acids. IV. Synthesis of (Hydroxyethyl)-azetidinone Precursors to 1-Thia Analogs of Thienamycin
Yoshida, Akira,Hayashi, Teruo,Takeda, Noriko,Oida, Sadao,Ohki, Eiji
, p. 2899 - 2909 (2007/10/02)
The synthesis of hydroxyethylazetidinone precursors to 1-thia analogs of thienamycin is described.An N-protected azetidinone 4 was hydroxyethylated via an aldol reaction to give four diastereomers 5-8, which were converted to the diastereomeric pair of racemic 8R and 8S trans azetidinones 9b and 10b.Stereochemical assignment was achieved by correlation of 9b with the optically active azetidinone 16 which was obtained from the hydroxyethylpenicillanate 14a with known stereochemistry.The optically active 8R and 8S azetidinones 16 and 27 were synthesized more efficiently starting from the penicillinderived bromo compound 19 in a series of steps including stereochemical inversion at the C-8 position.Keywords-- antibiotics; β-lactam; hydroxyethylazetidinones; aldol reaction; aluminium enolate of β-lactam; stereochemical inversion; triphenylphosphine/diethyl azodicarboxylate system; penicillin degradation
