Total synthesis palau’amine

As might be expected, the complex bisguanidine-containing hexacyclic skeleton of palau amines stimulated a series of creative synthetic efforts, but, while some moieties of the palau amine skeleton have been prepared, a total synthesis is still lacking [82-84]. 

The intramolecular Pauson-Khand reaction has been extensively used as a key step in total synthesis of fairly complex polycyclic natural products. The [2 + 2 + IJcycloaddition was, for example, used in recent syntheses of magellanine (Scheme 269), tecomanine, toward palau amines and styloguanidines (Scheme 270), Sa-hydroxystreptazolone (Scheme 271), ceratopicanol (Scheme 272), 13-deoxyserratine (Scheme 273), ABC-rings of nakadomarin and manzamine (Scheme 274), cedrone (Scheme 275), (-)-dendrobine (Scheme 276), " toward kalmanol (Scheme 277), and (+)-epoxydictymene (Scheme 278). 

The structural revision of marine natural product palau amine and total synthesis of the latter and related pyrrole-imidazole alkaloids 07AG(E)6586. 

Vhh conplings together with chemical shifts have been calcnlated by Chini et al for kedarcidin chromofore and palau amine in the attempt to establish the correct configuration of these two compoimds prior to their total synthesis. Kedarcidin chromofore is a compoimd that belongs to the enediyne family of antitumor antibiotics, whereas palau amine is an oroidin dimer, belonging to the class of pyrrole-imidazole alkaloid family isolated from the sponge Stylotella aurantiwn. Populations of conformers in three cinchona alkaloid O-ethers at ambient and low temperatnres have been estimated by Bnsygin et al ... 

Scheme 13.10 Total synthesis of palau amine (73) through two one-pot cascade transformations.

Seiple IB, Su S, Young IS, Lewis CA, Yamaguchi J, Baran PS. Total synthesis of palau amine. Angew. Chem. Int. Ed. 2010 49 1095-1098. 

The fist total synthesis of palau amine 247 was reported by Baran and co-workers (Scheme 43.42). The secondary... 

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