title: Total Synthesis of (+)-Gelsedine.
abstract: A novel iodide-promoted, allene-terminated cyclization of an N-acyliminium ion, a stereoselective Heck spirocyclization, and a chemoselective demethylation at the nitrogen atom of an oxindole are the key transformations in the first total synthesis of the indole alkaloid (+)-gelsedine (1). This dextrorotatory form of natural gelsedine was formed as a single enantiomer in 21 steps from (S)-malic acid.
authors.affiliation: Laboratory of Organic Chemistry, Institute of Molecular Chemistry, University of Amsterdam, Nieuwe Achtergracht 129, 1018 WS Amsterdam (The Netherlands).
authors.lastname: Beyersbergen van Henegouwen WG
authors.initials: RM
authors.lastname: Fieseler
authors.initials: FP
authors.lastname: Rutjes
authors.initials: H
authors.lastname: Hiemstra