title: Stereocontrolled synthesis of phosphorothioate RNA by the oxazaphospholidine approach.
abstract: Stereoregulated diribonucleoside phosphorothioates were synthesized by the use of 2'-O-TBDMS-protected ribonucleoside 3'-O-oxazaphospholidine derivatives as monomers and N-(cyanomethyl)ammonium salts as activators. Diastereoselectivity of the condensation reaction was found to be highly dependent on the substituent groups of the oxazaphospnolidine ring as well as the structure of the activators. By the use of the optimized oxazaphospholidine monomers and activators, diastereopure diribonucleoside phosphorothioate bearing Rp and Sp configurations were obtained in good yields.
authors.affiliation: Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Bioscience Bldg 702, Kashiwa, Chiba 277-8562, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Wada
authors.forename: Satoshi
authors.initials: S
authors.lastname: Fujiwara
authors.forename: Terutoshi
authors.initials: T
authors.lastname: Sato
authors.forename: Natsuhisa
authors.initials: N
authors.lastname: Oka
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Saigo
mesh_terms: D010080:Oxazoles / Q000737:chemistry*; D012313:RNA / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism; D013873:Thionucleotides / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: C470122:(1,3,2)oxazaphospholidine; D010080:Oxazoles; D013873:Thionucleotides; D012313:RNA