title: Efficient synthesis of the azaspirocyclic core structure of halichlorine and pinnaic acid by intramolecular acylnitroso ene reaction.
abstract: [reaction: see text] A new efficient strategy for the construction of the 6-azaspiro[4.5]decane ring system was developed using intramolecular ene reaction of the acylnitroso compound. The spirocyclic ene product obtained as a single diastereomer was subsequently subjected to highly stereoselective ethynylation, leading to the azaspirodecane core of halichlorine and the pinnaic acids.
authors.affiliation: School of Pharmacy, Tokyo University of Pharmacy & Life Science, Horinouchi, Hachioji, Tokyo 192-0392, Japan.
authors.forename: Yosuke
authors.initials: Y
authors.lastname: Matsumura
authors.forename: Sakae
authors.initials: S
authors.lastname: Aoyagi
authors.forename: Chihiro
authors.initials: C
authors.lastname: Kibayashi