Electrophilic aromatic prenylation via cascade cyclization

TETRAHEDRON

卷:69

Article

Kodet, John G.¹  Topczewski, Joseph J.¹  Gardner, Kevyn D.¹  Wiemer, David F.¹ 

[1] Univ Iowa, Dept Chem, Iowa City, IA 52242 USA

关键词: Cationic;    Cyclization;    Electrophilic aromatic substitution;    Prenylation;    Tandem reactions;   

DOI  :  10.1016/j.tet.2013.08.056

来源: Elsevier

【 摘 要 】

To gain access to prenylated hexahydroxanthenes, tandem cascade cyclization-electrophilic aromatic substitution reactions have been studied on substrates bearing allylic and propargylic substituents. Both BF3 center dot OEt2 and TMSOTf can be used to initiate this reaction sequence, resulting in different ratios of the C-2 and C-6 substitution products. Even though allylic transposition is observed in some cases, the results of a crossover experiment are consistent with an intramolecular reaction sequence. Taken together, these studies now allow preparation of either the C-2 or C-6 prenylated hexahydroxanthene products. (C) 2013 Elsevier Ltd. All rights reserved.

【 授权许可】

Free