ABSTRACT
A concise synthesis of erysotramidine (an alkaloid belonging to the erythrina family) was achieved starting with an inexpensive phenol and amine derivative. The synthesis is based on oxidative phenol dearomatizations mediated by a hypervalent iodine reagent and includes a novel route to a key indolinone moiety.
Subject(s)
Amines/chemistry , Erythrina/chemistry , Heterocyclic Compounds, 4 or More Rings/chemistry , Heterocyclic Compounds, 4 or More Rings/chemical synthesis , Indoles/chemistry , Phenol/chemistry , Alkaloids/chemical synthesis , Cyclization , Molecular Structure , StereoisomerismABSTRACT
Oxidative 1,2- and 1,3- alkyl shifts mediated by a hypervalent iodine reagent were performed on simple and inexpensive phenol derivatives. These transpositions enable rapid redesign of the main aromatic skeleton to generate good yields of highly functionalized scaffolds containing a prochiral dienone system, a quaternary carbon center connected to as many as four sp(2) centers, and a carbonyl functionality or precursor. An efficient enantioselective version of this process resulting in the formation of a challenging quaternary carbon center is also described. The products represent the central cores of several natural products having important bioactivities. As an illustration of the potential of this method, we describe the rapid synthesis of several functionalized polycyclic systems as well as a formal synthesis of acetylaspidoalbidine, a hexacyclic alkaloid belonging to the Aspidosperma family.
