A first resource-efficient and highly flexible procedure for a four-component synthesis of dispiropyrrolidines

Two series of dispiropyrrolidine derivatives were successfully synthesized by a tandem Knoevenagel-1,3-dipolar cycloaddition reaction sequence of isatin or acenaphthylene-1,2-dione, sarcosine, 1,3-indanedione, and an aldehyde without any catalyst. This strategy is not only suitable to aromatic aldehydes but aliphatic and heteroaromatic aldehydes as well, Moreover, this one-pot, four-component synthesis of dispiropyrrolidines is the first of its kind, as the dipole azomethine ylide and dipolarophile can be generated in situ. Such a strategy would provide access to a fast one-pot synthesis of dispiroheterocycles, which are otherwise accessible only through multistep synthesis. ((c) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008).