Sc(OTf)3-catalyzed synthesis of polysubstituted furans from acylacetonitriles and renewable acetol

A [3 ​+ ​2] cyclization reaction of acylacetonitriles and hydroxyacetone was developed by using Sc(OTf)3 as a catalyst to synthesize some furan derivatives. Bifunctional C2-based acetals, such as α-bromoacetaldehyde acetal, 1,4-dithiane-2,5-diol and glycolaldehyde diethyl acetal, also reacted readily as alternative counterpart reagents to acylacetonitriles. The established reactions can be used to synthesize a well-known fungicide, fenfuram. Antifungal activity investigation against four common plant funguses indicated that some of the obtained furan products furnish general and high biological activities.