title: Study on disulfur-backboned nucleic acids: part 3. Efficient synthesis of 3',5'-dithio-2'-deoxyuridine and deoxycytidine.
abstract: 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.
authors.affiliation: Key Laboratory of Phosphorus and Chemical Biology, The Ministry of Education, Department of Chemistry, Tsinghua University, Beijing, PR China.
authors.forename: Peihua
authors.initials: P
authors.lastname: Shang
authors.forename: Hua
authors.initials: H
authors.lastname: Wang
authors.forename: Changmei
authors.initials: C
authors.lastname: Cheng
authors.forename: Hongchao
authors.initials: H
authors.lastname: Zheng
authors.forename: Yufen
authors.initials: Y
authors.lastname: Zhao
mesh_terms: D003841:Deoxycytidine / Q000138:chemical synthesis / Q000737:chemistry*; D003857:Deoxyuridine / Q000138:chemical synthesis / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D009696:Nucleic Acids / Q000138:chemical synthesis / Q000737:chemistry*
chemical_list: D009696:Nucleic Acids; D003841:Deoxycytidine; D003857:Deoxyuridine