One-shot treatment of a mixture of Danishefsky diene 4 and tetraallyltin 8 with 3-formylbenzylidene imines 1 in the presence of Sc(OTf)3 catalyst provides a single product 13 as a result of exclusive Diels–Alder and allylation reactions on the imine and aldehyde functions, respectively. The chemoselectivities of the respective elementary reactions are improved in the parallel reaction, and the redistribution