Abstract: This paper presents the design of an undergraduate experiment utilizing the rare-earth catalyst ErCl₃·6H₂O to promote the one-step synthesis of cyclopent-2-enone derivatives. This reaction involves the biomass platform compound furfural and the commodity chemical dibenzylamine, proceeding via a Nazarov reaction and 4π-electrocyclization to afford important synthon cyclopentyl-2-enone derivatives in high yield. The experiment consists of four main stages: synthesis, filtration, recrystallization, and characterization. The project is characterized by its mild reaction conditions, non-toxic reagents, straightforward operation, good reproducibility, short reaction time, and high product yield, ideal for undergraduate laboratory courses. Furthermore, the experiment introduces important concepts such as green chemistry, high-value transformation of biomass platform compounds, and the theme of rare-earth metal catalysis. This project not only enriches the undergraduate experiment course, but also enhances the students’ interest and accomplishment in chemistry.

Key words: Green chemistry, Rare earth metal catalysis, Erbium(III) chloride, Biomass resources, Furfural