Strain-Barrier Stabilized Products from the Fischer Indole Synthesis. Compounds Containing the 4H-Imidazopyrroloindole and Dipyrrolodiazetodiindole Ring Systems

Article abstract of DOI:10.1055/s-1986-31758

The angular 3a-amino groups of 3a-amino-1,3a,4,8b-tetrahydro-pyrrolo<3,4-b>indol-3(2H)-ones fail to undergo the expected spontaneous elimination (as ammonia) which would introduce a 3a-4 double bond.The resistance of the amino group to elimination is such