Nucleoside und Nucleotide, Teil 12. Synthese von Dinucleosidmonophosphaten mit 1‐(2′‐Desoxy‐β‐ D ‐ribofuranosyl)‐2(1 H )‐pyrimidon als Baustein

Nucleosides and Nucleotides. Part 12. Synthesis of Dinucleoside Monophosphates Containing 1‐(2′‐Deoxy‐β‐ D ‐ribofuranosyl)‐2(1 H )‐pyrimidone The connexion of the modified nucleoside 1‐(2′‐deoxy‐β‐ D ‐ribofuranosyl)‐2(1 H )‐pyrimidone (M d , 2 ) with the natural nucleotides pT d and pG d is described. The protected dinucleoside monophosphates (MeOTr)M d pT d ( 6 ) and (MeOTr)M d pG   d ib( 9 ) were prepared by the standard phosphodiester method using DCC as condensing agent. M d pT d ( 7 ) was obtained by treatment of 6 with formic acid/methanol 7 : 3 at 0° 9 was converted to the free dinucleoside monophosphate M d pG d ( 11 ) by removing the N ‐isobutyryl‐ and p ‐methoxytrityl protecting group on consecutive treatment with 0.04 N CH 3 ONa in CH 3 OH and HCOOH/CH 3 OH 7:3 at 0° respectively. Enzymatic degradation of the free dinucleoside of the free dinucleoside monophosphates 7 and 11 yielded the corresponding nucleosides and nucleotides in the correct ratios.