Fischer Carbene Catalysis of Alkynol Cycloisomerization: Application to the Synthesis of the Altromycin B Disaccharide
作者:BonSuk Koo、Frank E. McDonald
DOI:10.1021/ol070435s
日期:2007.4.1
[reaction: see text] The tungsten-catalyzed cycloisomerization of alkynyl alcohols can be conducted without using photochemistry, using a stable tungsten Fischer carbene as the precatalyst for this transformation. A variety of alkynyl alcohols undergo cycloisomerization under these conditions to provide endocyclic enol ethers of five-, six-, and seven-membered ring sizes. The utility of this method is further
Discovery of the tungsten carbonyl-catalyzed endo-selective alkynyl alcohol cycloisomerization reaction: applications to stereoselective syntheses of d-olivose, d-olivose disaccharide substructures of landomycin and mithramycin
作者:Frank E McDonald、K.Subba Reddy
DOI:10.1016/s0022-328x(00)00643-4
日期:2001.1
An account of the discovery of the tungsten carbonyl-catalyzed endo-selective cycloisomerization of alkynyl alcohols to dihydropyrans is described. The utility of this new chemical transformation involving tungsten vinylidene catalytic intermediates is demonstrated in stereoselective syntheses of disaccharide substructures 26-28 of the landomycin and mithramycin families of anticancer antibiotics. (C) 2001 Elsevier Science B.V. All rights reserved.