Synthesis of Flexible Difluorinated Cyclopropanoid Nucleoside Analogues. -A novel class of difluorinated cyclopropanoid nucleoside analogues is synthesized. Coupling of a cyclopropane derivative with adenine or the appropriate pyrimidine base proceeds under Mitsunobu conditions to afford the protected adenine analogue. The latter is subsequently deacetylated using a catalytic amount of sodium methylate in methanol. Cis-and trans-substituted cyclopropane derivatives are treated in the same manner. Deacetylation and debenzoylation of (XIV) is performed in 2 steps to avoid decomposition under treatment with sodium hydroxide. -(CSUK, R.; EVERS-MANN, L.