220141-63-9Relevant academic research and scientific papers
Formal stereoselective synthesis of (±)-akagerine
Bennasar, M.-Lluisa,Vidal, Bernat,Sufi, Bilal A.,Bosch, Joan
, p. 2639 - 2640 (1998)
A stereoselective synthesis of pentacyclic dilactam 1, a known precursor of the indole alkaloid akagerine, involving addition of the enolate of 1-acetylindole 2 to 3-acetyl-2-fluoropyridinium salt 3, cyclization of the resultant 1,4-dihydropyridine, elabo
Nucleophilic Addition of 1-Acetylindole Enolates to Pyridinium Salts. Stereoselective Formal Synthesis of (±)-Geissoschizine and (±)-Akagerine via 1,4-Dihydropyridines
Bennasar, M.-Lluisa,Jimenez, Juan-Miguel,Vidal, Bernat,Sufi, Bilal A.,Bosch, Joan
, p. 9605 - 9612 (2007/10/03)
Addition of the enolate derived from 1-acetylindole (3) to pyridinium salt 4b followed by acid-induced cyclization of the resulting 1,4-dihydropyridine 5b in the presence of lithium iodide gives tetracyclic 3,7-methano[1,4]diazonino[1,2-a]indole 6b, which has subsequently been elaborated into the (E)-ethylidene derivative 7b. From this compound is reported a stereocontrolled route to (±)-geissoschizine, involving closure of C ring by Pummerer reaction, methanolysis of the resulting pentacyclic lactam 12, and desulfurization. A similar synthetic sequence starting from the enolate of 3 and 2-fluoropyridinium salt 15b gives access to the pentacyclic dilactam 2, which had previously been converted to (±)-akagerine through opening of the piperidone (D) ring.
