| Abstract: | Nucleosides of Fluorine Carbohydrates. XVI. Halogene Substitutions and Inversion of Configuration at the Lactol Ring of 6′-Fluoro-D-glucopyranosyl Thymine 1-(6′-Deoxy-6′-fluoro-β-D-glucopyranosyl)-thymine 1 reacts with equimolar amounts' of tosyl chloride to give the 2′-O-tosyl derivative 2 . Treatment of 1 with mesyl chloride gives predominantly a derivative with three sulfonyl groups in the molecule. 2 reacts both with bromides and iodides but not with fluorides to give the corresponding 2′-deoxy-2′-halogeno derivatives. 2 can be transformed into an 2,2′-anhydronucleoside 10 that reacts with HCl, HBr and HF/AlF3 to give the 2′-chloro-, 2′-bromo-, and 2′-fluoro derivatives of 1-(2′,6′-dideoxy-6′-fluoro-β-D-glucopyranosyl)-thymine 7 , 12 , and 13 respectively. Hydrogenation of 7 affords the 6′-fluoro analog of the nucleoside phosphorylase inhibitor “deoxyglucosyl thymine” possessing a defined β-configuration. The alkaline hydrolysis of the anhydronucleoside 10 yields the 1-(6′-deoxy-6′-fluoro-β-D-mannopyranosyl)-thymine 15 , the epimer of 1 . |
