A Novel Synthesis of the Macrocyclic Spermidine Alkaloid (+)‐(S)‐Dihydroperiphylline

A novel, short, and highly stereoselective synthesis of the macrocyclic spermidine alkaloid (+)‐(S)‐dihydroperiphylline ( 15 ) is described. The key synthetic steps were the stereoselective addition of the chiral amine 1 to the cinnamate 2 and cyclization of the bis[toluene‐4‐sulfonamide] precursor 12 in the presence of Cs₂CO₃ as a template. Unambiguous assignments of the signals in both the ¹H‐ and ¹³C‐NMR spectra of 15 were achieved by 2D NMR spectra.