- CARBACEPHEM BETA-LACTAM ANTIBIOTICS
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Carbacephem β-lactam antibiotics having structure (I) are disclosed, including stereoisomers, pharmaceutically acceptable salts, esters and prodrugs thereof, wherein Ar2, X, R1 and R2 are as defined herein. The compounds are useful for the treatment of bacterial infections, in particular those caused by methicillin-resistant Staphylococcus spp.
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Page/Page column 71-72
(2010/04/06)
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- Enantioselective synthesis of the carbacephem antibiotic loracarbef via Mitsunobu and Dieckmann cyclization from an unnatural amino acid
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The nucleus of the carbacephem antibiotic loracarbef was synthesized in a highly efficient and enantioselective fashion from 2S,3S-2-amino-3-hydroxy-6-heptenoic acid (AHHA), which was derived from enzyme-catalyzed condensation of glycine and 4-pentenaldehyde. The bicyclic framework of this compound was established through sequential Mitsunobu reaction and aldol condensations.
- Misner, Jerry W.,Fisher, Jack W.,Gardner, John P.,Pedersen, Steve W.,Trinkle, Kristina L.,Jackson, Billy G.,Zhang, Tony Y.
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p. 5991 - 5993
(2007/10/03)
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- Methods and compounds for the preparation of carbacephems
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A chiral process for preparing compounds of the formula: STR1 from a compound of the formula: STR2 in which the compound formula (IV) is reacted with trimethylsilyl iodide to remove the chiral auxiliary at the 7-position and the carboxy protecting group. The process allows for the retention of the amino and carboxy protecting groups throughout the preparation of Compound IV. Also disclosed are novel intermediates.
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- Enantioselective synthesis of loracarbef from sodium erythorbate
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Sodium erythorbate (7) has been converted to loracarbef (1). Oxidation of sodium erythorbate to D erythronolactone (8) followed by selective monotosylation and treatment with sodium ethoxide provided ethyl (2S,3R) 4 hydroxy 2.3 epoxybutyrate (10). Swern oxidation of this epoxide into the aldehyde (11), imine formation with tert-butylglycinate and an enantioselective Staudinger reaction with phthalimidoacetyl chloride afforded the (3S,4S)-cis-β-lactam (13). Appropriate functional group manipulations followed by a Dieckmann condensation, chlorination, and protecting group removals gave the enantiomerically pure nucleus of loracarbef (24).
- Frazier, Jeffery W.,Staszak, Mike A.,Weigel, Leland O.
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p. 857 - 860
(2007/10/02)
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