Preparation of methyl 2,3-di-O-mesyl-4,6-thioanhydro-α-d-galactopyranoside and methyl 2-O-mesyl-4,6-thioanhydro-α-d-gulopyranoside Original Research Article

Two 2-oxa-7-thiabicyclo[4.2.0]octane derivatives, 4 and 10, with the d-galacto and d-gulo configuration, respectively, were obtained from methyl α-d-glucopyranoside. The thietane cyclization involved a thio-Mitsunobu reaction resulting in a 6-thioacetate, which underwent selective base-catalyzed intramolecular nucleophilic substitution at a C-4 mesylate. The structureS of 4 and 10 were elucidated by X-ray diffraction analysis.