Stereoselective tandem Michael-intramolecular cyclization approach to functionalized pyrroloisoindolones

Article abstract of DOI:10.1016/S0040-4020(99)00645-6

A stereoselective synthesis of pyrrolo[2,1-a]isoindol-5-ones is described. The synthesis takes place through a tandem Michael addition- intramolecular cyclization, by the base-promoted condensation of methyl N- phthaloylalaninate with conjugate acceptors at low temperature. The desired products were obtained in good yields as single isomers in only one step. Presumably, the stereoselectivity of the cyclization step is kinetically controlled by a lithium chelate species between the interacting centers. The structure of the adducts is discussed, being supported by NMR experiments and X-ray crystallography.