The remaining challenge in the total synthesis of lapparbin (1) lies in the introduction of the side chain to the cyclized products 25 and 28, which contain the highly strained Tyr-Trp linkage. While preparative thin-layer chromatography (PTLC) allowed for the separation of cyclized products 25/28 on a small scale, separation by column chromatography on a 9.9 g scale proved difficult, necessitating the use of the mixture in subsequent reactions. The methyl ester of cyclized products 25/28 was hydrolyzed with LiOH, yielding the corresponding carboxylic acid. Subsequently, amidation with a two-residue amino acid fragment 29 produced compound 30. Following Boc deprotection, compound 30 was subjected to amide coupling with Boc-Lalanine (31), affording compound 32. Employing the same methodology, Boc-glycine (8) and two Boc-L-alanine (31) residues were sequentially condensed with compound 32, resulting in compound 34 with a high isolated yield. Furthermore, deprotection of compound 34 followed by amidation with Bocglycine (8) yielded 1.5 g of protected lapparbin (35). Finally, the first total synthesis of lapparbin (1) was achieved by deprotecting the phenolic Me group with BBr3, followed by LiOH-mediated hydrolysis of the Me-ester.