Ring Opening of Alkynyl Sugars by Nicholas Reaction----Application to Enantioselective Synthesis of Oxepane Subunits of Marine trans-fused Polyether Toxins

Article abstract of DOI:10.1016/S0040-4020(01)81207-2

Pyranose ring of cobalt-complexed alkynyl sugars was cleaved by Nicholas reaction.The reaction of 22 was diastereoselective and this selectivity was presumably due to steric interaction between cobalt acetylene moiety and tert-butyldiphenylsilyloxy functi