169220-16-0Relevant articles and documents
Mannich biscyclizations. Total synthesis of (-)-ajmalicine
L?gers, Michael,Overman, Larry E.,Welmaker, Gregory S.
, p. 9139 - 9150 (2007/10/02)
A concise enantioselective total synthesis of the cardiovascular agent (-)-ajmalicine and an approach toward the synthesis of (+)-19-epiajmalicine 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.
