Efficient approach to 2-hydroxy-2,3-dihydrofuran derivatives and its application for the synthesis of novel 4-(1H-pyrazol-4-yl)pyridazines.

A highly efficient method for the synthesis of 2-hydroxy-2,3-dihydrofuran derivatives from 1,4-enediones and phenacyl pyridinium halides via a domino reaction has been developed. This is a simple and beneficial strategy for the construction of 2-hydroxy-2,3-dihydrofuran compounds from readily available starting materials under mild conditions. Moreover, the application of this reaction provides a straightforward and practical route for the synthesis of the novel 4-(1H-pyrazol-4-yl)pyridazine skeleton.