P-stereodefined boranophosphate 2′-O-Me-oligoribonucleotides (2′-O-Me-PB-ORNs) were synthesized and we revealed that an all-(Sp)-PB-backbone largely stabilized the duplex with RNA.
Nucleotides, Part LX, Synthesis and Characterization of New 2′-O-Methylriboside 3′-O-Phosphoramidites Useful for the Solid-Phase Synthesis of 2′-O-Methyloligoribonucleotides
A series of new 2'-O-methylribonucleoside 3'-O-[2-(4-nitrophenyl)ethyl dialkylphosphoramidites] 27-31, 33-38, 40-44, and 45-50 were synthesized and their stability and rc activity compared in automated oligonucleotide synthesis with the standard 2'-O-methylribonucleoside 3'-O-(beta-cyanoethyl diisopropylphosphoramidites) 32, 39, 45, and 51, respectively. The 2-(4-nitrophenyl)ethyl (npe) and 2-(3-nitrophenyl)ethoxycarbonyl (npeoc) groups were used for the protection of the base moieties.
Nucleosides. Part LXI. A Simple Procedure for the Monomethylation of Protected and Unprotected Ribonucleosides in the 2?-O- and 3?-O-Position Using Diazomethane and the Catalyst Stannous Chloride
作者:Hagen Cramer、Wolfgang Pfleiderer
DOI:10.1002/hlca.19960790808
日期:1996.12.11
Intensive studies on the diazomethane methylation of the common ribonucleosides uridine, cytidine, adenosine, and guanosine and its derivatives were performed to obtain preferentially the 2′-O-methyl isomers. Methylation of 5′-O-(monomethoxytrityl)-N2-(4-nitrophenyl)ethoxycarbonyl-O6-[2-(4-nitrophenyl)ethyl]-guanosine (1) with diazomethane resulted in an almost quantitative yield of the 2′- and 3′-O-methyl