| 摘要 |
Regiospecific synthesis of optionally 2- and/or 4- substituted 5'-(5-amino-imidazol-1-yl)-5'-desoxyglucofuranose inverse nucleosides of formula (I) and optionally 4-substituted 5'-(5-amino-triazol-1-yl)-5'-desoxyglucofuranose inverse nucleosides of formula (II) and their analogues, as well as their 1,5'-cyclo-5-(5'-desoxy- beta - D-glucofuranosyl amino -imidazole and -triazole polycyclic derivatives of formulae (III) and (IV), comprises: (a) synthesis of an N-cyanomethyl alkyl imidate if imidazole-type inverse nucleosides or their analogues are to be prepared; (b) regiospecific synthesis of imidazole- or triazole-type inverse nucleosides or their analogues; (c) intramolecular cyclisation to give an oxadiazepine heterocycle. Step (c) may be followed by modification of groups X and Y, one of these modifications creating an additional heterocycle linking the exocyclic N atom of B or C to the C4 atom on B or C. In unit A: R1-R4 = H, OH, CN, N3, halo, ether, acetal, acid, amide, imidate or amine; R5 = OH, OR, or OCOR; R = alkyl, allyl, benzyl, aryl or forms part of a 1,2-acetal group; R6 = H, CH2OH, CH2OR, CH2OCOR' or haloalkyl; R' = alkyl, allyl, benzyl, aryl or haloalkyl; halo = Cl, Br, or F; In unit B, X = H, alkyl, aryl, For units B and C, Y = aldehyde, ketone, nitrile, ester, amide or is such that it forms a heterocycle with the exocyclic N on rings B or C. (I)-(IV) are claimed per se. |
