Studies on Transfer Ribonucleic Acids and Related Compounds. XXVII. Linear and Cyclic Oligonucleotides obtained by Polymerization of Protected Ribonucleoside 3'-Phosphates

Abstract

An improved method for the dicyclohexylcarbodiimide-catalyzed polymerization of protected ribonucleoside 3'-phosphates (Cp, Ap, Up or Gp) is described. The formation of 5'-O-pyridinium compounds was eliminated and various 5'-O-monomethoxytritylated protected homooligonucleotides could be rapidly isolated in reasonable yields. The isolation and purification of 3', 5'-cyclized oligonucleotides (cCpCp, cUp (Up)_n or cGpGp) are described.