The plausible biosynthetic pathway of pyrrovobasine (1) is shown in Figure . After removal of the alcohol moiety of vobasinol (2), the C2 position of the tryptamine derivative 4 with the pyrraline structure is linked to the activated vobasinol derivative 3 to form pyrrovobasine (1). It is known that sugar derivatives such as hexose react with amine residues of amino acids and proteins by Maillard-type reactions. Tryptamine derivative 4 is thought to be formed by the enzymatic decarboxylation of L-tryptophan followed by the reaction of the amino group with hexose in a Maillard-type reaction. Based on the biosynthetic pathway described above, we planned to introduce the tryptamine and pyrraline skeletons at the end of the synthesis.