An approach to the intramolecular Diels-Alder reaction has led to a cascade synthesis of complex carbocycles composed of three fused rings and up to five stereocentres with complete stereocontrol. Computational analysis reveals that the reaction proceeds via a Michael-Michael-cyclopropanation-epimerization cascade, in which size and coordination of the counterion is key.
Keywords:
cations
,heterocycles
,density-functional calculations
,cycloadditions
,diastereoselectivity
