2-Isocephems

A -0-2-Isocephem-4-carboxylic acid, 1-P-phenoxyacetamido-3-methyl-1 -oxo-synthesis, 1, 430 Isochroman, 1,3-diphenyl-synthesis, 3, 787, 788 Isochroman, 3,4-diphenyI-conformation, 3, 631 Isochroman, 2-methyl-synthesis, 3, 788 Isochroman, 3-phenyl-synthesis, 3, 788 Isochroman, (-)-)-(i )-3-phenyI-stereoselective synthesis, 3, 789 Isochroman-4-carboxylic acid, l-oxo-3-phenyl-synthesis, 3, 860 Isochroman-I,3-diones, 4-acyI-synthesis, 3, 831 Isochromanols dehydration, 3, 767 isochroman synthesis from, 3, 789 Isochroman-1-one, 3-aryl-synthesis, 3, 858, 860... 

Electrophilic Azidation of Chiral Lactone Enolates to Give 2-Isocephem... 

The lactone 2 is transformed via several steps into the 7-azido-2-isooxaphem 3 and the 7-azido-2-isocephem 4. Reduction of the azide groups, acylation and removal of the protecting groups gives the corresponding cephalosporin derivatives stereospecifically. 

Benzo-O-2-isocephems are obtained in high yield by fluoride-induced cyclization of readily available monocyclic /3-lactams (Scheme 138), and details of two essentially similar syntheses of 2,3-benzo-fused 1-oxacephems have appeared (Scheme 139). ... 

TABLE XXIII Antimicrobial Activity of 7a-Methoxy Analog of 2-lso and 0-2-Isocephems ... 

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