Towards the total synthesis of RP 66453: a neurotensin antagonist with a twist

This thesis describes the efforts made towards the total synthesis of RP 66453, a highly strained macrocyclic tetrapeptide. RP 66453 provides an interesting synthetic challenge, not only due to its potential biological activity but also owing to its unusual chemical architecture. The strained bicyclic ring system features a 15-membered macrocycle containing an aryl-aryl bond and a 14-membered meta,para-cyclophane.Herein, several strategies towards the model A-B macrocycle of RP 66453 are presented featuring as a key step, a radical induced transannular ring contraction of a benzyl haloaryl ether and a photochemical transannular cyclisation of cis-stilbene derivatives. Synthetic efforts towards the B-O-C macrocycle are also presented, including copper-mediated and intramolecular SNAr cyclisation strategies. Finally, research into the union of these two fragments is presented followed by a discussion of a proposed end-game strategy