Fischer carbene catalysis of alkynol cycloisomerization: application to the synthesis of the altromycin B disaccharide.
[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 demonstrated in the stereoselective synthesis of the disaccharide substructure of altromycin B.
Koo
Bonsuk
B
Department of Chemistry, Emory University, Atlanta, Georgia 30322, USA.
McDonald
Frank E
FE
D000438:Alcohols / Q000737:chemistry*; D000480:Alkynes / Q000737:chemistry*; D000617:Aminoglycosides / Q000737:chemistry*; D002384:Catalysis; D003500:Cyclization; D004187:Disaccharides / Q000138:chemical synthesis / Q000737:chemistry*; D006838:Hydrocarbons / Q000737:chemistry; D007536:Isomerism; D008697:Methane / Q000031:analogs & derivatives* / Q000737:chemistry; D015394:Molecular Structure; D010777:Photochemistry
D000438:Alcohols; D000480:Alkynes; D000617:Aminoglycosides; D004187:Disaccharides; D006838:Hydrocarbons; C063717:altromycin B; C030011:carbene; D008697:Methane