An improved diastereoselective synthesis of spiroazoles using multicomponent domino transformations

Article abstract of DOI:10.1055/s-0030-1258516

Spiroisoxazole and spiropyrazole derivatives were obtained in a four-component reaction of active isoxazol- or pyrazol-5-ones with aromatic aldehydes, phenacyl chloride and AcOH-AcONH₄ mixture. The reaction sequence is highly chemo- and diastereoselective affording good yields of spiroisoxazoles in refluxing ethanol, while efficient formation of spiropyrazoles is closely related to the use of a microwave-assisted protocol.