The structures of three new dimeric indole alkaloids, ervahanine A, B and C, 1-3, have been elucidated from a detailed study of the and 13C nmr spectra and subsequently by partial synthesis. These alkaloids are of the voacamine type lacking the methoxy substituent and are isomeric at positions C-11’, C-10’ and C-12’ with respect to the ibogane moiety. © 1981, American Chemical Society. All rights reserved.