Nature-Inspired Stereospecific Total Synthesis of P-(+)-Dispegatrine and Four Other Monomeric Sarpagine Indole Alkaloids

摘要

The sarpagine-macroline group of indole alkaloids (biogenet-ically related to the ajmaline-related alkaloids) consists of more than 150 members and is an important class of natural products with diverse biological activity. Common to these three classes of alkaloids is the core cycloocta[&]indole framework A (Figure 1 a), which has recently been a subject of biology-oriented synthesis (BIOS), the analogues of which are promising targets for developing a novel class of potent and selective Mycobacterium protein tyrosine phosphatase B (MptpB) inhibitors against Mycobacterium tuberculosis. The S configuration at C6 and CIO and the 兝-ketoester moiety were key to the inhibitory activity.