Chiral 2-Thioxotetrahydro-1,3-O,N-heterocycles from Carbohydrates. 2. Stereocontrolled Synthesis of Oxazolidine Pseudo-C-nucleosides and Bicyclic Oxazine-2-thiones

Article abstract of DOI:10.1021/jo00071a032

Chiral, sugar-derived oxazolidine-2-thiones having a pseudo-C-nucleoside structure, as well as bicyclic 2-thioxotetrahydro-1,3-oxazines, have been prepared by intramolecular cyclization of 6-deoxy-6-isothiocyanatoaldoses or -aldopyranosides, respectively.The reaction proceeds with total regioselectivity and no need for protection of the secondary hydroxyl groups.A one-pot procedure for the synthesis of the five-membered heterocycles from the corresponding amino sugars is aslo reported.The six-membered analogs have a cis- or trans-decalin-type core depending on the configuration of the sugar precursor.