Synlett 1991; 1991(10): 723-724
DOI: 10.1055/s-1991-34778
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A Facile One-Pot Synthesis of Isocoumestans via a Novel Extension of the Castro Cyclization of o-Iodophenols and Ethyl Propiolate

Olof Haglund* , Martin Nilsson
  • *Department of Organic Chemistry, Chalmers University of Technology, S-412 96 Göteborg, Sweden
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Publication History

Publication Date:
13 March 2002 (online)

Treatment of o-iodophenols with ethyl propiolate in the presence of copper(I) tert-butoxide affords isocoumestans (6H-benzofuro[2,3-c][1]benzopyran-6-ones) in a one-pot synthesis. The reaction is considered to be an extended Castro cyclization where an intermediate cupriated benzofuran couples with additional o-iodophenol, and the product lactonizes to isocoumestan.

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