title: The thio-Mitsunobu reaction: a useful tool for the preparation of 2,5-anhydro-2-thio- and 3,5-anhydro-3-thiopentofuranosides.
abstract: The unprotected methyl L-arabinofuranosides, D-ribofuranosides and D-xylofuranosides are transformed into the corresponding S-acetyl-5-thio derivatives by the thio-Mitsunobu reaction. Mesylation and subsequent reaction with sodium hydrogen carbonate led, depending on the configuration of the intermediate, to 2,5-anhydro-2-thio- or 3,5-anhydro-3-thiopentofuranosides. Due to inversion at C-3 or C-2 during the intramolecular nucleophilic displacement the products exhibit L-lyxo-, D-arabino- or D-lyxo-configuration. Analogously, the methyl 2,3-anhydro-D-ribofuranosides yielded 5-thio-S-acetates with intact 2,3-oxirane groups, which were cyclised with sodium hydrogen carbonate by epoxide ring opening and concomitant ring closure to form exclusively 3,5-anhydro-3-thio-D-xylofuranosides. A related 3,5-anhydro-3-seleno-D-lyxofuranoside was obtained by reaction of a 3,5-di-O-mesyl-D-arabinofuranoside with sodium hydrogen selenide. Several X-ray diffraction analyses proved the structures of the products.
authors.affiliation: Institut für Organische Chemie der Universität Hamburg, Martin-Luther-King-Platz 6, D-20146 Hamburg, Germany. olli@ukezyk.desy.de
authors.forename: Oliver
authors.initials: O
authors.lastname: Schulze
authors.forename: Jürgen
authors.initials: J
authors.lastname: Voss
authors.forename: Gunadi
authors.initials: G
authors.lastname: Adiwidjaja
authors.forename: Falk
authors.initials: F
authors.lastname: Olbrich
mesh_terms: D000085:Acetates / Q000737:chemistry; D001089:Arabinose / Q000737:chemistry*; D001639:Bicarbonates / Q000737:chemistry; D001669:Biochemical Phenomena; D001671:Biochemistry; D018360:Crystallography, X-Ray; D005663:Furans / Q000737:chemistry; D006859:Hydrogen / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D008956:Models, Chemical; D008958:Models, Molecular; D064586:Selenic Acid; D018036:Selenium Compounds / Q000737:chemistry; D012964:Sodium / Q000737:chemistry; D014961:X-Ray Diffraction; D014994:Xylose / Q000737:chemistry
chemical_list: D000085:Acetates; D001639:Bicarbonates; D005663:Furans; D018036:Selenium Compounds; D006859:Hydrogen; D012964:Sodium; D014994:Xylose; D001089:Arabinose; D064586:Selenic Acid; C026372:hydrogen selenide