Metal-Templated Macrolactamization of Triamino and Tetramino Esters. Facile Synthesis of Macrocyclic Spermidine and Spermine Alkaloids, (S)-(+)-Dihydroperiphylline, (.+-.)-Buchnerine, (.+-.)-Verbacine, (.+-.)-Verbaskine, and (.+-.)-Verbascenine.