Divergent synthesis of 2-C-branched pyranosides and oxepines from 1,2-gem-dibromocyclopropyl carbohydrates
作者:Peter W. Moore、Julia K. Schuster、Russell J. Hewitt、M. Rhia L. Stone、Paul H. Teesdale-Spittle、Joanne E. Harvey
DOI:10.1016/j.tet.2014.06.069
日期:2014.9
The ring opening of 1,2-(gem-dibromo)cyclopropyl carbohydrates by two different modes leads to either 2-C-(bromomethylene)pyranosides (using base) or 2-bromooxepines (using silver salts), as shown previously by us for a d-glucal-derived cyclopropane. The base-promoted ring opening is extended to encompass additional alcohol, thiol and amine nucleophiles, and diastereoisomeric cyclopropane precursors