Cytidine 2-thio

O. Kanie, J. Nakamura, M. Kiso, and A. Hasegawa, Stereoselective synthesis of 5 -.V-(5-acetamido-3,5-dideoxy-D-g/ycero-a- and - 3-D-galacfo-2-nonulopyranosylonic acid)-5 -thio-cytidine, J. Carbohydr. Chem. 6 105 (1987). 

The order of preference of RNase T2 for various bonds in RNA is ApN > UpN > GpN > CpN (55), so no general rule can be stated for the preference for purine or pyrimidine, or for keto or amino substituent. Recently, it was found that RNase T2 gave complete cleavage of the phosphodiester bonds of 4-thiouridylate in tRNA (55) and of 6-thio-guanylyl-(3 -5 )-cytidine (27). This shows that the substitution of sulfur at the 4 position of pyrimidine base or at the 6 position of purine base does not effect the action of RNase T2. Furthermore, the phosphodiester bonds of the nucleotides with a large substituent at the 6 position of purine base such as A6-isopentenyladenosine (57), 2-methyl thio-N6-(A2-... 

Reist and coworkers [9,10] described the first sulfur-containing furanose rings. They prepared 4-thio-D-ribofuranose 14 (Figure 9.4) and 4-thio-L-ribofuranose via nucleophihc displacement of the tosylate in 2,3-(9-isopropylidene-4-(9-toluenesulfonyl-a-D- and -a-L-lyxopyranosides, respectively, with potassium thiobenzoate in DMF. Several nucleosides of 4-thiofuranoses were subsequently synthesized. For example, the 4 -thio analog 15 of natural thymidine and the corresponding derivative of cytidine were prepared by Whistler and coworkers [11]. 

Regioselectively protected cytidine derivatives have been prepared from the peracetylated nucleoside using lipase and esterase reactions. There have been reports on the use of bacterial proteases for the selective acylation of sucrose to produce a variety of different acyl and acrylate esters. 8-Aminooctyl 5-5-coniferyl-5-thio-a-L-arabinofuranoside(27) attached to sepharose proved to be a selective affinity ligand for feruloyl esterase A. niger ... 

Uracil and cytosine derivatives of 4-thio-DL-erythrofuranose and adenine and guanine nucleoside analogues of 4-thio-D-ribofuranose, 4-thio-D-xylofuranose, and 5-thio-D-xylopyranose have been reported. Treatment of 2,2 -anhydro-cytosine with phosphorus pentasulphide gave the cyclic thiophosphate derivatives (49), which was used to prepare other 2 -thio-cytidine derivatives. The... 

A -Acetyl-3, 5 -0-(tetraisopropyldisiloxane-l,3-diyl)cytidine, T-38 iV-Acetyl-5-thio-D-glucosamine, A-349 iV-Acetylthomosamine, A-377 iV-Acetyl-2,3,4-tri-0-acetyl-D-ribosylamine, R-145 iV-Acetyl-2,3,4-tri-0-acetyl-D-xylosamine, X-88 A-Acetyl-2,3,4-tri-0-acetyl-L-xylosamine, X-88... 

Using a reaction sequence involving dibutylstannylation and displacement of triflate, new 2 -substituted-2 -deoxyarabinofuranosyl adenine derivatives have been prepared (Scheme 12) the products (92) and (93) were converted into the corresponding 2 -amino- and 2 -thio-ara6mo-nucleosides. A communication, with no synthetic details, on the preparation and use of 2 -azido-and 2 -amino-2-deoxy-j8-D-arabinofuranosyl cytidine as cytotoxic agents has been published. ... 

There has been a further report on the introduction of the [[2-(methylthio)phenyl]thio] methyl (MPTM) protecting group into the 2 -position of adenosine, guanosine and cytidine building blocks for oligonucleotide synthesis (See Vol. 25, p. 270).300 Some thioacetals and dithioorthoesters at 0-5 of FdU, such as 213 have been prepared and subjected to y-radiolysis.30i... 

Fox s group has extended its work on the synthesis of pseudocytidine ( -cyti-dine) (Vol. 9, p. 148) to include other 5-D-ribofuranosylpyrimidines. Thus the 3-methoxyacrylate derivative (436) reacted with guanidine, urea, or thiourea to give derivatives of i -cytidine, -uridine, and 2-thio- -uridine and their a-anomers. The D-ribofuranosyl-ethyne and -ethene derivatives (437) and... 

The sialic acid-cytidine conjugate 83 has been synthesized, the units being linked by displacement of a 5 -bromo-substituent on the nucleoside by a 2-thio-sialyl nucleophile. ... 

There have been fewer cytidine analogues reported, and by far the most publications concern 5-hydroxymethylcytidine. 2-Thiocytidine has been incorporated into the anticodon stem-loop sequence of S. aureus tRNA using standard phosphoramidite chemistry but using t-butyl peroxide in toluene as oxidant.2-Thio-5-methyl-dC has also been used in triplex oligonucleotides where it aided stabilisation of a G-C base pair without protonation. ... 

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