(Chemical Equation Presented) 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 π-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).
ASJC Scopus subject areas
- Organic Chemistry