ChemInform Abstract: Studies Toward the Total Synthesis of the Oxindole Alkaloid Gelsedine: An Efficient Allene-Terminated N-Acyliminium Ion Cyclization.

✍ Scribed by W. G. BEYERSBERGEN VAN HENEGOUWEN; H. HIEMSTRA

• Publisher: John Wiley and Sons
• Year: 2010
• Weight: 33 KB
• Volume: 29
• Category: Article
• ISSN: 0931-7597
• DOI: 10.1002/chin.199816219

✦ Synopsis

Studies Toward the Total Synthesis of the Oxindole Alkaloid Gelsedine: An Efficient Allene-Terminated N-Acyliminium Ion Cyclization.

-The preparation of the advanced synthetic intermediate (VII) in the projected synthesis of enantiopure ent-gelsedine is reported. The use of the inexpensive (S)-enantiomer as starting material led to the ent-gelsedine, but this was preferred over a racemic synthesis. Four new stereocenter with complete control of stereochemistry are created in the route from only one in the starting (S)-malic acid. The novel title cyclization is the key step which leads to the required skeleton of (VI). -(BEYERSBERGEN VAN HENEGOUWEN, W.