Progress in 7-deazapurine - pyrrolo[2,3-d]pyrimidine - ribonucleoside synthesis.

This review reports on the synthesis of 7-deazapurine ribonucleosides, including C-nucleosides, 2'-C-methyl derivatives and L-enantiomers. It covers the various aspects of convergent nucleoside synthesis such as the Schiff base procedure, the fusion reaction, the metal salt procedures, the Silyl-Hilbert-Johnson reaction, and the nucleobase anion glycosylation. The review discusses the scope and limitations of glycosylation reactions performed on 7-deazapurines. Peracylated ribose derivatives were now employed in the glycosylation, which overcome difficulties reported earlier.