Direct synthesis of γ-pyrones by electrophilic condensation of β-ketoesters†
Antonio Misale,Florian Schiel,Nuno Maulide
Organic & Biomolecular Chemistry Pub Date : 12/15/2016 00:00:00 , DOI:10.1039/C6OB01884J
Abstract

Triflic anhydride is a versatile electrophile that is able to activate poor nucleophiles. Herein, we show that readily available β-keto esters are activated by Tf2O furnishing γ-pyrones. Mechanistic studies suggest that this transformation proceeds via a double triflation, formation of an oxocarbenium intermediate and dealkylation promoted by a crucial nitrile additive.

Graphical abstract: Direct synthesis of γ-pyrones by electrophilic condensation of β-ketoesters