Synthetic analogues of polynucleotides. Part IX. Synthesis of 3′-O-carboxymethyl-2′-deoxyribonucleosides and their use in the synthesis of an analogue of 2′-deoxyadenylyl-(3′→ 5′-)-thymidine 3′-phosphate

Abstract

3′-O-Carboxymethyl-5′-O-triphenylmethyl-2′-deoxycytidine, 3′-O-carboxymethyl-2′-deoxyguanosine, 3′-O-carboxymethyl-5′-O-(4-methoxyphenyldiphenylmethyl)-2′-deoxyadenosine and 3′-O-carboxymethyl-2′-deoxyadenosine have been synthesised by the action of sodium chloroacetate on suitably protected deoxyribonucleosides. The 2,2,2-trichloroethyl group has been shown to be suitable for the protection of the carboxy-group during the synthesis of polynucleotide analogues containing acetate ester linkages, and superior to the 2-cyanoethyl group used hitherto. The dinucleotide analogue. 2′-deoxyadenosinylacetyl-(3′→ 5′)-thymidin-3′-ylacetic acid has been synthesised; it shows a hyperchromic effect of 5% at 248 nm and 6·7% at 260 nm upon hydrolysis of the internucleoside linkage.