| Popis: |
2′,5′-Dideoxy-5′-fluororibonucleosides are conveniently obtained by treatment of the corresponding 5′- O -tosyl 1 derivatives with an excess of tetrabutylammonium fluoride in N,N -dimethylformamide at 50°. The p.m.r. spectra of the fluoro derivatives establish unequivocally their structure. Surprisingly, treatment of 3′,5′-di- O -mesylthymidine 1 with potassium fluoride or with tetrabutylammonium fluoride gave mesylanhydrothymidines rather than fluorine-containing products. Under similar conditions, 5′-deoxy-5′-iodothymidine was converted mainly into 4′,5′-unsaturated 5′-deoxythymidine. |
