| Popis: |
The 1′-cyano-2′,3′-D-unsaturated nucleoside 8 was synthesised according to the following steps. Photobromination of the ribofuranosyl cyanide 1 using N-bromosuccinimide (NBS) as a radical source gave the two isomers of the new C-1 gem disubstituted sugar 2 . Its condensation with silylated thymine afforded the blocked nucleoside 3 , the stereochemistry and molecular shape of which were deduced from NMR studies and molecular simulation. After deprotection of 3 into 4 , thiocarbonylation of the silylated derivative 5 , followed by olefination of 6 , led to 7 which was deblocked to the 1′-cyano substituted d4T 8 . |
