Abstract
Mitsunobu coupling of 3-hydroxymethylbenzofurans with o-iodophenols affords 3-(2-iodophenoxy)methylbenzofurans which under go a useful 6-endo Heck cyclization under Jeffery conditions to afford pterocarpene-type heterocycles. The unsubstituted parent pterocarpene thus prepared was readily converted to coumestan via subsequent PCC oxidation.
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ACKNOWLEDGMENTS
We gratefully acknowledge the donors to the Petroleum Research Fund, administered by the American Chemical Society, for partial support of the work. K. F. also thanks the Department of Chemistry for a summer research fellowship.