Synthesis of pyranose glycals via tungsten and molybdenum pentacarbonyl-induced alkynol cyclizations

Article abstract of DOI:10.1016/S0040-4020(97)00366-9

The tungsten pentacarbonyl-induced cyclization of an acyclic alkynol substrate bearing protected oxygen and nitrogen functional groups provides the cyclic tungsten oxacarbene, which is readily converted into a pyranose glycal structurally related to the carbohydrate moieties of the pluramycin and vancomycin families of antitumor antibiotics. In addition a molybdenum-catalyzed cycloisomerization procedure provides an alternative route to this pyranose glycal.