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 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
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.