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Updated: Sep 23, 2025

Metal-free Synthesis of Ynones from Acyl Chlorides and Potassium Alkynyltrifluoroborate Salts
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α,β-Unsaturated Carbonyls for One-Pot Transition-Metal-Free Access to 3,6-Dihydro-2H-pyrans
Pankaj Kumar1, Navpreet Kaur1, Rakesh Kumar1
1Department of Chemistry, Indian Institute of Technology Ropar, Rupnagar, Punjab 140001, India.
Abstract:
An efficient protocol has been developed for accessing mono-, di-, and trisubstituted 3,6-dihydro-2H-pyran derivatives by simply subjecting α,β-unsaturated carbonyls to the carefully optimized Corey-Chaykovsky reaction conditions. The strategy provides selectively substituted dihydropyran derivatives in good to excellent yields with a broad substrate scope under very mild reaction conditions. Easy transformation of the final 3,6-dihydro-2H-pyran to the valued 5,6-dihydro-2H-pyran-2-one and tetrahydro-2H-pyran derivatives expanded the scope of this methodology to diverse oxacycles. Further, the developed strategy also found application in a two-step route to racemic goniothalamin, which is widely studied for its cytotoxic behavior.
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