A General Strategy for Synthesis of Heterocyclic Hemiketal-Containing α,β-Unsaturated Ketones from Ynediones

A general strategy for synthesis of heterocyclic hemiketal-containing α,β-unsaturated ketones has been established. Using the environmentally sound and readily available reagents water and thiourea applied to ynediones, a series of sensitive hemiketals of 3(2H)-furanones and 3(2H)-thienones were constructed under mild conditions. Both of the reaction conditions are compatible with a diverse range of functional groups. Isotopic labeling, tautomerism, and GC-MS tracking methods were used to reveal the mechanisms. He ain't hemi: A general strategy for synthesis of heterocyclic hemiketal-containing α,β-unsaturated ketones has been established, and a series sensitive hemiketals of 3(2H)-furanone and 3(2H)-thienone were constructed from ynediones under mild conditions. Isotopic labelling, tautomerism, and GC-MS tracking investigations revealed the mechanisms.