Stereochemistry of 1,3-dipolar-cycloaddition of 3,4-dihydro-isoquinoline- and 3,4-dihydro-carboline-N-methoxycarbonyl- and N-phenacyl-methylides with maleic and fumaric nitrile

The 1,3-dipolar-cycloadditions of two kind of isoquinolinium and carbolinium ylides with fumaric and maleic nitrile resulted in pyrroloisoquinoline and indolizino[8,7-b]indole derivatives, respectively, which are analogues of biologically active alkaloids. The cycloadditions were performed in good yield and proved to be stereoselective. The structure elucidation and complete H-1 and C-13 assignments have been achieved by a combination of various one- and two-dimensional NMR experiments.