Synthesis of Nα-Fmoc N,N′-bis-Boc-5-, 6- and 8-guanyl-1,2,3,4-tetrahydroisoquinoline-3-carboxylic Acid (5-GTIC, 6-GTIC and 8-GTIC) - Severino, Beatrice; Santagada, Vincenzo; Frecentese, Francesco; Perissutti, Elisa; Terracciano, Sara; Fiorino, Ferdinando; Cirillo, Donatella; Salvadori, Severo; Balboni, Gianfranco; Caliendo, Giuseppe (Synthesis, 2004)