Synthesis of polycyclic spirooxindoles an asymmetric catalytic one-pot stepwise Aldol/chloroetherification/aromatization procedure

A general method for the synthesis of chiral pentacyclic spirooxindoles containing a tetrahydropyrano[2,3- b ]indole scaffold through a one-pot stepwise sequence from 3-(3-indolomethyl)oxindole, paraformaldehyde and NCS is reported. Furthermore, the pentacyclic spirooxindoles could be transformed to bispirooxindole and other structurally diverse spirocyclic oxindoles. A general method for the synthesis of chiral pentacyclic spirooxindoles containing a tetrahydropyrano[2,3- b ]indole scaffold through a one-pot stepwise sequence is reported.