Gardneria nutans gardnerine from

Gardnerine (28), one of the major indole alkaloids of Gardneria nutans 21), was converted into koumidine (1) (22). The crucial steps in this transformation are deoxygenation from the indole ring by Pd°-assisted reduction of the aryl trifiate derivative (31) and inverting the configuration of the ethylidene side chain in 32 by Pd° catalyst (Scheme 4). 

---