Diethylene Glycol Serving as Ethyne Equivalent: A Sustainable Approach toward 2,3-Disubstituted Furan

In the presence of tert-butyl peroxide (TBHP), the copper-catalyzed annulation of 1,3-dicarbonyl compound with diethylene glycol was developed leading to 2,3-disubstituted furan. Diethylene glycol serves as a cheap and environmentally friendly equivalent of ethyne, with the release of H2O and alcohol as clean wastes. The procedure involves a sequential O- and C- functionalization of β-ketoester by diethylene glycol.