| Abstract: | A route for synthesizing C-nucleosides with 2,6-substituted pyridines as heterocyclic aglycones is described. Condensation of appropriately substituted lithiated pyridines with ribono-1,4-lactone derivatives yields hemiacetal 4a – g (Table 1), which can be reduced by Et3SiH and BF3·Et2O to the corresponding C-nucleoside (see Scheme 1 for 4d → β-D - 5 ). Conditions are presented that optimize the amount of the 2,6-dichloropyridine-derived β-D -anomer β-D - 5 formed (Table 3). Aminolysis of β-D - 5 yields the diaminonucleoside 14 (Scheme 3). |
