Transglycosylation Reaction of 6-Thioguanosine.

Abstract Peracetylated 6-thioguanosine (2) undergoes the so far unknown N→S transglycosylation reaction to form a stable 9,S6 -bis(ribosyl) derivative (3) and N2-acetyl-6-thioguanine (4). The reaction takes place at elevated temperatures with no catalyst, or in solution in the presence of acidic catalysts. The reversible 79 isomerization, characteristic for guanosine and its analogs, has not been observed in this case.