Synthesis and Antimicrobial Activity of Unsaturated Ketones Containing a Furan Fragment

Unsaturated ketones of the furan series have been synthesized by the aldol–crotonic condensation of furfural with some unsaturated ketones. The optimal conditions have been found to include alcoholic sodium hydroxide as reaction medium and room temperature, which provide higher regioselectivity, 65–75% yields of the target unsaturated ketones, and the absence of byproducts. The presence of a C=C double bond activated by the carbonyl group in the molecules of the synthesized unsaturated ketones makes them promising substrates for the preparation of various potentially biologically active compounds. In particular, they reacted with hydrazine hydrate, thiosemicarbazide, and secondary amines to give new furan derivatives.