Abstract
The syntheses of novel structurally intriguing hexacyclic cage-like compounds have been achieved from the three-component tandem [3+2] cycloaddition-intramolecular annulation reactions of ninhydrin, alpha-amino acids and (E)-3-arylidene-1-methylpiperidin-4-ones. On the other hand the four-component reactions of ninhydrin, o-phenylenediamine, alpha-amino acids and (E)-3-arylidene-1-methylpiperidin-4-ones afforded novel polycyclic dispiro compounds. (C) 2015 Elsevier Ltd. All rights reserved.