Organic & biomolecular chemistry

Gold-catalyzed cycloisomerization of alk-4-yn-1-ones

V Belting, N Krause

Index: Belting, Volker; Krause, Norbert Organic and Biomolecular Chemistry, 2009 , vol. 7, # 6 p. 1221 - 1225

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Citation Number: 59

Abstract

Depending on the substitution pattern and the solvent, the gold-catalyzed cyclization of alk-4- yn-1-ones 1 affords different oxygen heterocycles under mild reaction conditions. Alkynones with one substituent at C-3 undergo a 5-exo-dig cycloisomerization to substituted furans 2, whereas a 6-endo-digcyclization to 4H-pyrans 3 is observed with substrates bearing two substituents at C-3. In alcoholic solvents, alkylidene/benzylidene-substituted ...