Rapid and efficient stereocontrolled synthesis of C-3′-ethynyl ribo and xylonucleosides by organocerium additions to 3′-ketonucleosides
摘要:
In order to prepare new anti-retroviral nucleoside analogues, the effect of the group at C-5' on the addition of lithium and cerium trimethylsilylacetylide on 3'-ketonucleosidcs (R(1) = H, R(1) = TBDMS) derived from adenosine and uridine was studied. The best results in respect of yield (56 to 81%) and diastereoselectivity (95:5 to >98:2) were obtained with a cerium reagent (RCcCl(2)).