Synthesis of dimethyl gloiosiphone a by way of palladium-catalyzed domino cyclization

Takayuki Doi; Yusuke Iijima; Masaru Takasaki; Takashi Takahashi

doi:10.1021/jo062546v

Synthesis of dimethyl gloiosiphone a by way of palladium-catalyzed domino cyclization

J Org Chem. 2007 May 11;72(10):3667-71. doi: 10.1021/jo062546v. Epub 2007 Apr 12.

Authors

Takayuki Doi¹, Yusuke Iijima, Masaru Takasaki, Takashi Takahashi

Affiliation

¹ Department of Applied Chemistry, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro, Tokyo 152-8552, Japan.

PMID: 17428095
DOI: 10.1021/jo062546v

Abstract

The synthesis of a spiro[4.4]nonane skeleton by the palladium-catalyzed domino cyclization of a linear 7-methylene-2,10-undecadienyl acetate is described. The pi-allylpalladium intermediate underwent intramolecular alkene insertion with high intraannular diastereoselectivity, followed by intramolecular Heck-type cyclization, leading to a spiro[4.4]nonane system. Oxidation of the allylic ether moiety and transformation of the vinyl group to an exo-methylene unit provided 3, which is the known synthetic intermediate of dimethyl gloiosiphone A (2).