One-pot synthesis of pyrrolooxazoles from pyrrolyl acetylenic ketones and natural aldehydes

Natural aldehydes and some of their derivatives undergo base-catalyzed [3 + 2]-cyclization with pyrrolyl acetylenic ketones in a click-like manner (Et₂O, KOH, room temperature) to afford pyrrolo[1,2-c]oxazoles in up to 77% yield, a novel family of pharmaceutically prospective compounds.