HPLC of Tropane Alkaloids

Tropane alkaloids can be divided into two series depending on the spatial orientation of the hydroxyl group at C-3 [1]. Derivatives of tropan-3α-ol (e.g., tropanol) are by far the most common, and those of tropan-3β-ol are essentially specic to the Erythroxylaceae. They are meso compounds, and the two bridgehead carbons have opposite chirality. Their hydroxylated forms are esteried with different types of optically active acids [1,2]; however, if other substituents are absent, the tropanols are optically inactive. The tropanols are often hydroxylated at C-6 or C-7 or both, and sometimes 6,7-epoxidized. In Figure 31.1 the structures of typical tropanols are presented, whereas in Figure 31.2, some of the tropane alkaloids in their esteried original forms are shown.