A facile synthesis of 2-(3-alkynyl-2,3-dihydrobenzofuran-3-yl)acetate

Abstract

A facile synthesis of 2-(3-alkynyl-2,3-dihydrobenzofuran-3-yl)acetate (1a, 1b), with a unique alkynyl-benzylic quaternary center on a dihydrobenzofuran ring, was accomplished. The key step of the synthesis is the aryl radical cyclization to the tethered enyne carboxylate to generate the unique alkynyl-benzylic quaternary center. The synthesis started from simple building blocks with high flexibility and constructed the complex template in a total of four steps. With several functional groups available, compounds of structure 1a and 1b could be easily further derivatized.