Synthesis of Polysubstituted 2H-Pyran-2-ones or Phenols via One-Pot Reaction of (E)-β-Chlorovinyl Ketones and Electron-Withdrawing Group Substituted Acetates or β-Diketones

Abstract

This paper describes a facile one-pot synthesis of highly functionalized 2H-pyran-2-ones and phenols through a base-promoted annulation of readily available β-chlorovinyl ketones with various active methylene compounds. Conjugate addition of electron-withdrawing group substituted acetates to allenone intermediates and direct conjugate addition of β-diketones to β-chlorovinyl ketones reveal versatile electrophilic pathways of β-chlorovinyl ketones under different reaction conditions. In particular, cyclocondensation is regiospecific for 3,5-disubstituted phenols. Moreover, the utility of [3+3] cyclocondensation is further illustrated by the concise synthesis of benzofuran derivative and penta- or hexa-substituted phenol construction.