Synthesis and spectral properties of cytosine nucleosides of 2-amino-2-deoxy-alpha-D-arabino-furanose and -pyranose.
Ethyl 2-deoxy-3,5-di-O-p-nitrobenzoyl-1-thio-2-(trifluoroacetamido)-beta-D-arabinofuranoside (3) was converted into the glycosyl chloride. Condensation of the latter with 2,4-dimethoxypyrimidine, followed by amination, gave 1-(2-amino-2-deoxy-alpha-D-arabinofuranosyl)cytosine (6), which was also obtained from the alpha-D anomer (4) of 3. Similarly, 1-(2-amino-2-deoxy-alpha-D-arabinopyranosyl)cytosine (12) was synthesized from ethyl 2-deoxy-3,4-di-O-p-nitrobenzoyl-1-thio-2-(trifluoroacetamido)-alpha-D-arabinopyranoside (9). The p.m.r. spectra of these nucleosides, as well as those of the 1-thioglycosides, are discussed in terms of the conformation of the sugar portion. In particular, a large change of the J1,2 coupling constants of the alpha-D-furanosides, according to the substituents at C-1 and C-2, was interpreted on the basis of conformational mobility.
D001089:Arabinose; D002942:Circular Dichroism; D003596:Cytosine / Q000031:analogs & derivatives* / Q000138:chemical synthesis; D009682:Magnetic Resonance Spectroscopy; D008722:Methods; D008968:Molecular Conformation; D009904:Optical Rotation; D013055:Spectrophotometry, Infrared; D013056:Spectrophotometry, Ultraviolet
D003596:Cytosine; D001089:Arabinose