Alstoscholarisines H–J, Indole Alkaloids from <i>Alstonia scholaris</i>: Structural Evaluation and Bioinspired Synthesis of Alstoscholarisine H

Alstoscholarisines H–J (<b>1</b>–<b>3</b>), new monoterpenoid indole alkaloids with an unprecedented skeleton created via the formation of a C-3/N-1 bond, were isolated from <i>Alstonia scholaris</i>. Their structures were established by extensive spectroscopic analyses and the assessment of single-crystal X-ray diffraction data. The total synthesis of alstoscholarisine H was achieved via the regioselective nucleophilic addition of pyridinium through a bioinspired iminium ion intermediate followed by Pictet–Spengler-like cyclization