A new route is presented to prepare analogs of nucleosides homologated at the 3'-and 5'- positions. This route, applicable to both the d-and l-enantiomeric forms, is suitable for the preparation of monomeric bishomonucleosides needed for the synthesis of oligonucleotide analogs. It begins with the known monobenzyl ether 3 of pent-2-yne-1, 5-diol, which is reduced to alkenol 4. Sharpless asymmetric epoxidation of 4, followed by opening of the ...
