Double [3 + 2] cycloadditions for diastereoselective synthesis of spirooxindole pyrrolizidines

One-pot two sequential [3 + 2] cycloadditions of azomethine ylides with different dipolarophiles for diastereoselective synthesis of spirooxindole pyrrolizidines are introduced. This one-pot synthesis involving five components generates a highly condensed ring system bearing seven stereocenters diastereoselectively. The new method has high pot, atom, and step economy. Only two equivalents of water are released as a side product.