title: Additive Pummerer reaction of 3,5-O-(di-tert-butyl)silylene-4-thiofuranoid glycal: a high-yield and beta-selective entry to 4'-thioribonucleosides.
abstract: Upon reacting 3,5-O-(di-tert-butyl)silylene-4-thiofuranoid glycal S-oxide (6) with Ac(2)O/TMSOAc/BF(3) x OEt(2) in CH(2)Cl(2), the additive Pummerer reaction proceeded to furnish the corresponding 1,2-di-O-acetyl-4-thioribofuranose 7. Compound 7 serves as a highly beta-selective glycosyl donor in the Vorbruggen condensation carried out in the presence of TMSOTf. Thus, the 4-thio-beta-D-ribofuranosyl derivatives of uracil, thymine, N (4) -acetylcytosine, 6-chloropurine, and 2-amino-6-chloropurine were synthesized. The use of 7 can be extended to the beta-selective synthesis of 4'-thio-C-ribonucleosides.
authors.affiliation: School of Pharmaceutical Sciences, Showa University, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo 142-8555, Japan.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Haraguchi
authors.forename: Hiromitsu
authors.initials: H
authors.lastname: Matsui
authors.forename: Shin
authors.initials: S
authors.lastname: Takami
authors.forename: Hiromichi
authors.initials: H
authors.lastname: Tanaka
mesh_terms: D015075:2-Aminopurine / Q000031:analogs & derivatives / Q000138:chemical synthesis; D003596:Cytosine / Q000031:analogs & derivatives; D011687:Purines / Q000138:chemical synthesis; D012263:Ribonucleosides / Q000138:chemical synthesis*; D012833:Siloxanes / Q000737:chemistry*; D013872:Thionucleosides / Q000138:chemical synthesis*; D013876:Thiophenes / Q000737:chemistry*; D013941:Thymine / Q000031:analogs & derivatives; D014498:Uracil / Q000031:analogs & derivatives
chemical_list: C476353:4-thiofuranoid glycal; D011687:Purines; D012263:Ribonucleosides; D012833:Siloxanes; D013872:Thionucleosides; D013876:Thiophenes; D015075:2-Aminopurine; D014498:Uracil; C040510:2-amino-6-chloropurine; D003596:Cytosine; C079308:6-chloropurine; D013941:Thymine