Atom-Economic Synthesis of 4-Pyrones from Diynones and Water

Abstract

Transition-metal-free synthesis of 4-pyrones via TfOH-promoted nucleophilic addition/cyclization of diynones and water has been developed. This transformation is simple, atom economical and environmentally benign, providing rapid and efficient access to substituted 4-pyrones.

Regiodivergent Hydration–Cyclization of Diynones under Gold Catalysis

“…8 However, one of the simplest and most atom-economical approaches involves the hydration/cyclization of diynones or the cyclization of acetylenic -diketones. The first one has been developed by different authors towards the synthesis of 4-pyrones using Brønsted acids, such as triflic 9 acid or p-toluenesulfonic acid, 10 as catalysts (Scheme 1, eq 2). Nevertheless, this useful Scheme 1.…”