Synthesis of monoterpene alkaloid derivatives from the iridoid glucoside geniposide

Nine novel monoterpene alkaloid derivatives (3(a)-(c), 4(a)-(c), 5(a)-(c)) were prepared as a reaction of genipin 2 with L-amino acid methyl hydrochlorides utilized the reaction of reductive amination. Genipin was obtained by beta-glucosidase, catalyzed hydrolysis of the iridoid glucoside geniposide 1. The chemical structures were confirmed by 1D-, 2D-NMR and MS.