This thesis describes synthetic approaches directed towards the synthesis of the alkaloid natural products nitensidine D 213 and nitensidine E 214. The structurally less complex metabolite nitensidine D was prepared by the guanylation of commercially available geranylamine 254 whilst four synthetic approaches were attempted to prepare nitensidine E. Initially the 6-membered guanidines 225a-b, 256 and 257 were prepared via an iodocyclisation of the corresponding allylic 226a-b and homoallylic guanidines 255, whilst the guanidines 265a-b were prepared via a DMDO mediated epoxidation
and acid catalysed cyclisation/ rearrangement reaction. Attempts to convert these to the desired metabolite were unsuccessful. Finally, the cyclic guanidine 283 was prepared from the allylic acetate 281 via a palladium π-allyl cyclisation.