| Abstract: | The alpha-carbethoxypentadecyltrimethylammonium (Septonex) salt of tRNA (Ib) was condensed with ethyl N-benzyloxycarbonylorthoglycinate (II) in dimethylformamide in vacuo and in the presence of H3PO4 as catalyst. Pancreatic RNAase degradation and phenylalanine acceptor activity showed a 55--60% conversion to the 2',3'-cyclic orthoglycinate derivative of tRNA (IIIb). The orthoester grouping of IIIb was quantitatively hydrolyzed in 80% formic acid at 0 degrees C for 15 min to give 2'(3')-O-(N-benzyloxycarbonyl)glycyl tRNA (IVb). The latter was stripped at pH 8.8 to give tRNA whose behavior on DEAE cellulose column and gel electrophoresis was similar to that of starting tRNA. The phenylalanine acceptor activity amounted to almost 80% of the starting tRNA. |
