Automated RNA-synthesis with photocleavable sugar and nucleobase protecting groups

A new synthetic method for the N-alkyloxycarbonylation of adenine and guani ne nucleosides was developed and used for the preparation of RNA-phosphoram idites carrying photolabile sugar and nucleobase protecting groups. From th ese building blocks, a heptameric oligoribonucleotide was prepared by autom ated synthesis, followed by detachment from the solid support and photolyti c deprotection under mild conditions. The presented strategy allows a simpl e preparation of 3'-O-aminoacylated RNA-sequences.