Total Synthesis of (+)-Gelsedine.
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.
Beyersbergen van Henegouwen WG
Laboratory of Organic Chemistry, Institute of Molecular Chemistry, University of Amsterdam, Nieuwe Achtergracht 129, 1018 WS Amsterdam (The Netherlands).
Fieseler
RM
Rutjes
FP
Hiemstra
H