The title synthesis was achieved by featuring diastereoface selective cyclopropanation of (4R,5S)-4,5-diphenyl-3-vinyl-2-oxazolidinone, the chiral and conformationally rigid N-vinylcarbamate, with zinc-monofluorocarbenoid followed by hydrogenolysis of formed (4R,5S)-3-[(1R-2S)-2-fluorocyclopropyl]-4,5-diphenyl-2-oxalidinone.
The invention relates to novel 1,6-naphthyridonecarboxylic acid derivatives, to processes for their preparation, to antibacterial compositions and feed additives in which they are present, and to novel intermediates for the preparation of these active compounds.
The title synthesis was accomplished by featuring highly cis-selective cyclpropanation of an N-vinylcarbamate with zinc-monofluorocarbenoid followed by deprotection of the formed N-(cis-2-fluorocyclopropyl)carbamate. Optical resolution of dl-cis-2-fluorocyclopropylamine was also achieved by employing l-menthyl chloroformate as a resolving agent.
The title synthesis was achieved by featuring diastereoface-selective cyclopropanation of (4R,5S)-4,5-diphenyl-3-vinyl-2-oxazolidinone and its related compounds, the chiral conformationally rigid N-vinylcarbamates, with zinc-monofluorocarbenoid, followed by hydrogenolysis of the major addition products. The diastereoface-selectivity of the cyclopropanation could be explained by the most stable conformation
Synthetic studies on the key component of the new generation of quinolonecarboxylic acid, DU-6859. 1. Synthesis of (1R,2S)-2-fluorocyclopropylamine by the use of optical resolution
by employing highly cis-selective cyclopropanation of N-benzyl-N-vinylcarbamates with zinc-monofluorocarbenoid, deprotection of the formed N-benzyl-N-(cis-2-fluorocyclopropyl)carbamates, and opticalresolution of the resulting dl-cis-2-fluorocyclopropylamine by the use of l-menthyl chloroformate as a resolving agent. The cis-selectivity observed for the key cyclopropanation could be explained by the