New indole alkaloid analogues, containing a 10b-methyl- or a 10b-hydroxy-1,2,4,5,10b, 10c-hexahydropyrrolo[1',2',3':1,9a,9]imidazo[1,2-a] indole skeleton, have been obtained by highly stereoselective electrophile addition-cyclization reactions of a tryptophan-derived alpha-amino nitriles. (c) 2007 Elsevier Ltd. All rights reserved.