Shang Peihua, Wang Hua, Cheng Changmei, Zheng Hongchao, Zhao Yufen
Key Laboratory of Phosphorus and Chemical Biology, The Ministry of Education, Department of Chemistry, Tsinghua University, Beijing, PR China.
Nucleosides Nucleotides Nucleic Acids. 2008 Dec;27(12):1272-81. doi: 10.1080/15257770802520474.
A general method is described for synthesizing 3',5'-dithio-2'-deoxypyrimidine nucleosides 6 and 13 from normal 2'-deoxynucleosides. 2,3'-Anhydronucleosides 2 and 9 are applied as intermediates in the process to reverse the conformation of 3'-position on sugar rings. The intramolecular rings of 2,3'-anhydrothymidine and uridine are opened by thioacetic acid directly to produce 3'-S-acetyl-3'-thio-2'-deoxynucleosides 3 or 5. To cytidine, OH(-) ion exchange resin was used to open the ring and 2'-deoxycytidine 10 was obtained in which 3'-OH group is in threo-conformation. The 3'-OH is activated by MsCl, and then substituted by potassium thioacetate to form the S,S'-diacetyl-3',5'-dithio-2'-deoxycytidine 12. The acetyl groups in 3',5' position are removed rapidly by EtSNa in EtSH solution to afford the target molecules 6 and 13. The differences of synthetic routes between uridine and cytidine are also discusssed.
