| Abstract
| - The new pyrimidine derivatives of 2,3-O,O-dibenzyl-6-deoxy-l-ascorbic acid (8−10) weresynthesized by condensation of uracil and its 5-fluoro- and 5-trifluoromethyl-substitutedderivatives with 4-(5,6-epoxypropyl)-2,3-O,O-dibenzyl-l-ascorbic acid (7), while pyrimidinederivatives of 4,5-didehydro-5,6-dideoxy-l-ascorbic acid (14−17) with free C-2‘ and C-3‘ hydroxygroups in the lactone ring were obtained by debenzylation of 11−13 with boron trichloride.Z-Configuration of the C4‘C5‘ double bond and position of the benzyl group in the lactonering of 14 were deduced from their 1H and 13C NMR spectra and connectivities in COSY,ROESY, and HMBC spectra. The exact stereostructure of 13 was confirmed by its X-ray crystalstructure analysis. Of all the compounds in the series, compound 16 containing a 5-fluoro-substituted uracil ring showed the most significant antitumor activities against murineleukemia L1210/0 (IC50 = 1.4 μg/mL), murine mammary carcinoma FM3A/0 (IC50 = 0.78 μg/mL), and, to a lesser extent, human T-lymphocyte cells Molt4/C8 (IC50 = 31.8 μg/mL) and CEM/0cell lines (IC50 = 20.9 μg/mL).
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