Chemoselective Intramolecular Wittig Reactions for the Synthesis of Oxazoles and Benzofurans

A chemoselective approach was developed
for the synthesis of highly
functionalized oxazoles and benzofurans using an intramolecular Wittig
reaction as the key step. By choosing proper trapping reagent or method
of addition of reagents, chemoselectivity can be controlled toward
either oxazole or benzofuran derivatives.