MANNICH BISCYCLIZATIONS - TOTAL SYNTHESIS OF (-)-AJMALICINE

Authors
LOGERS M OVERMAN LE WELMALKER GS
Citation
M. Logers et al., MANNICH BISCYCLIZATIONS - TOTAL SYNTHESIS OF (-)-AJMALICINE, Journal of the American Chemical Society, 117(36), 1995, pp. 9139-9150
Citations number
66
Categorie Soggetti
Chemistry
Journal title
Journal of the American Chemical Society → ACNP
ISSN journal
00027863
Volume
117
Issue
36
Year of publication
1995
Pages
9139 - 9150
Database
ISI
SICI code
0002-7863(1995)117:36<9139:MB-TSO>2.0.ZU;2-O
Abstract
A concise enantioselective total synthesis of the cardiovascular agent (-)-ajmalicine and an approach toward the synthesis of (+)-19-epiajma licine are described. The key step of the (-)-ajmalicine synthesis is a carboxylate-terminated N-acyliminium ion biscyclization (74 --> 67), which assembles the D and E rings of this heteroyohimbine alkaloid in one step. A related carboxylate-terminated iminium ion biscyclization (28 --> 29) is the central step in the approach to (+)-epiajmalicine.