70337-80-3Relevant articles and documents
Functional Group Substitutions as Probes of Hydrogen Bonding between GA Mismatches in RNA Internal Loops
Santalucia Jr., John,Kierzek, Ryszard,Turner, Douglas H.
, p. 4313 - 4322 (2007/10/02)
The contribution of hydrogen bonding to the stability of GA mismatches in RNA is investigated by making functional group substitutions. Such substitutions are made possible by the chemical synthesis of RNA; chemical incorporation of purine riboside and 2-
THE p-NITROPHENYLETHYL (NPE) GROUP. A VERSATILE NEW BLOCKING GROUP FOR PHOSPHATE AND AGLYCONE PROTECTION IN NUCLEOSIDES AND NUCLEOTIDES
Himmelsbach, Frank,Schulz, Bernd S.,Trichtinger, Thomas,Charubala, Ramamurthy,Pfleiderer, Wolfgang
, p. 59 - 72 (2007/10/02)
The syntheses of new monomeric building blocks for oligonucleotide synthesis via the phosphotriester approach containing the p-nitrophenylethyl group for phosphate and aglycone protection are described.Blocking of the amide function in guanosines at O6 can be achieved by the Mitsunobu reaction forming the corresponding O6-p-nitrophenylethyl derivatives (4,5,10).Sugar-protected thymidine (16) and uridine (17) have been alkylated at O4 in an SN1-type reaction by p-nitrophenylethyl iodide-silver carbonate in benzene to form the O4-p-nitrophenylethyl derivatives (18,19).Protection of the amino group in 2'-deoxycytidine (25) and cytidine (26) can be performed directly by 1-(p-nitrophenylethoxycarbonyl)-benzotriazole in DMF to obtain the corresponding carbamates (27,28) as a new type of N4-acylated cytidine derivative. p-Nitrophenylethoxycarbonylation of the amino group in 2'-deoxyadenosine (33) and adenosine (34) requires previous sugar protection by acyl or silyl groups and can then be achieved by p-nitrophenylethyl chloroformate or better by 1-methyl-3-p-nitrophenylethoxycarbonylimidazolium chloride to form N6-p-nitrophenylethoxycarbonyladenosines (38,39,40,42).The various p-nitrophenylethyl blocking groups are stable under mild hydrolytic conditions (e.g. ammonia and triethylamine) but can be cleaved selectively by DBU or DBN in aprotic solvents. 5'-O-Monomethoxytritylation (12,29,43) as well as phosphorylations at the 3'-OH group can be effected to give the corresponding 3'-(2,5-dichlorophenyl,p-nitrophenylethyl)-phosphotriesters (13,22,30,44) also in high yields.Oximate cleavage of the latter compounds to the phosphodiesters (14,24,32,46) and detritylation to the 5'-unblocked phosphotriesters (15,23,31,45) do not affect the aglycone protecting groups, thereby demonstrating their general versatility.The newly synthesized compounds have been characterized on the basis of their elementary analyses (C,N,H), and UV- and 1H-HMR-spectra.
Nucleosides, XXXVII. - Synthesis and Properties of 2'-O- and 3'-O-(tert-Butyldimethylsilyl)-5'-O-(4-methoxytrityl)- and 2',3'-Bis(O-tert-butyldimethylsilyl)ribonucleosides - Starting Materials for Oligoribonucleotide Syntheses
Flockerzi, Dieter,Silber, Gunter,Charubala, Ramamurthy,Schlosser, Wilhelm,Varma, Rajendra Singh,et al.
, p. 1568 - 1585 (2007/10/02)
The synthesis of aminoacylated 5'-O-(4-methoxytrityl)ribonucleosides of adenosine (1), guanosine (9), cytidine (31), uridine (17), and 5,6-dihydrouridine (23) have been optimized and these compounds (4, 12, 33, 18 and 24) silylated by tert-butyldimethylsilyl chloride.The corresponding 2'- and 3'-mono-O- as well as 2',3'-bis-O-(tert-butyldimethylsilyl) derivatives have been isolated by combination of chromatographical methods and fractional crystallization procedures in preparative scale.The characterization of the newly synthesized compounds was achieved by UV and 13C-NMR spectra.
