RESUMO
The convergent synthesis of an unusual (but simple) class of compounds 5a-g has been achieved by the copper-catalyzed [3+2] cycloaddition reaction of 2,3,4,6-tetra-O-acetyl-beta-D-glucopyranosyl azide 4 with propynyl 3-[3-(aryl)-1,2,4-oxadiazol-5-yl] propionates 3a-g. The formerly known azide 4 has been prepared according to the literature procedure; however, the synthesis of esters 3a-g is being reported for the first time. The infrared as well as (1)H NMR spectra of all new products are in agreement with their proposed structures. By carrying out the nOe experiment of one of the final compounds 5a, we have been able to establish that only the 1,4-regioisomers have been formed in the cycloaddition reaction. All final products presented weak cytotoxic activity, but 5e and 5g had somewhat better behaviour showing 22-25% cell growth inhibition against two cell strains: NCI-H(292) (lung carcinoma) and HEp-2 (larynx carcinoma).
Assuntos
Antineoplásicos/química , Antineoplásicos/toxicidade , Oxidiazóis/química , Oxidiazóis/toxicidade , Triazóis/química , Triazóis/toxicidade , Antineoplásicos/síntese química , Carbono/química , Carcinoma/tratamento farmacológico , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Glicosilação , Humanos , Neoplasias Laríngeas/tratamento farmacológico , Neoplasias Pulmonares/tratamento farmacológico , Oxidiazóis/síntese química , Oxigênio/química , Triazóis/síntese químicaRESUMO
The reaction of a racemic mixture of (2R,2'S)- and (2S,2'R)-N-(p-tolylsulfonyl)-2-pyrrolidinyl-2-propanol, prepared from (S)-proline, with 2,3,4-tri-O-acetyl-alpha-L-fucopyranosyl trichloroacetimidate led to both diastereoisomers of the title compound after O-deacetylation.
Assuntos
Fucose/análogos & derivados , Fucose/química , Fucose/síntese química , Pirrolidinas/química , Pirrolidinas/síntese química , Estrutura Molecular , EstereoisomerismoRESUMO
1,3-Dipolar cycloaddition of methylideneaniline N-oxide to sugar enones is described. The addition occurred exclusively from the side opposite to the aglycone affording the corresponding alkyl alpha-D-lyxo-hexopyranosid-(2,3:5',4')-phenylisoxazolidin-4-uloses. Hydrogenation of these compounds readily yielded the corresponding alkyl 3-deoxy-3-N-phenylaminomethyl-alpha-D-talopyranoside, that were readily transformed to the acetates. The structure and conformation of the bicyclic compounds were determined by 1H NMR studies and semi-empirical molecular orbital calculations employing the AM1 method.