A short and efficient synthesis of the tRNA nucleosides PreQ0 and archaeosine

Abstract

Modified nucleosides in tRNAs play an important role in the translational process. They fine tune the codon–anticodon interactions and they influence the folding and stabilisation of the tRNA structure. Herein, we present a novel synthetic route to the highly modified nucleosidesPreQ0 and archaeosine. The synthesis involves coupling of a protected 7-cyano-7-deazaguanosine nucleobase with a TBDMS and isopropylidene protected chloro-ribose unit yielding the PreQ0nucleoside after deprotection. This PreQ0nucleoside is then used as the starting material for the synthesis of archaeosine providing the first total synthetic access to this hypermodified RNAnucleoside.