201225-11-8

Upstream product

• 24424-99-5 di-tert-butyl dicarbonate 
• 201225-31-2 2-Chloro-N-[2-(1H-indol-3-yl)-ethyl]-N-(4-oxo-cyclohexyl)-acetamide 
• 61-54-1 tryptamine 
• 201225-30-1 2-Chloro-N-(1,4-dioxa-spiro[4.5]dec-8-yl)-N-[2-(1H-indol-3-yl)-ethyl]-acetamide 
• 171367-14-9 (1,4-Dioxa-spiro[4.5]dec-8-yl)-[2-(1H-indol-3-yl)-ethyl]-amine 
• 4746-97-8 cyclohexanedione monoethylene ketal 

Relevant academic research and scientific papers

First Total Synthesis of (±)-Melinonine-E and (i)-Strychnoxanthine Using a Radical Cyclization Process as the Core Ring-Forming Step

The first total synthesis of (±)-melinonine-E and (±)-strychnoxanthine is described. The key common step for the synthesis of both alkaloids is the elaboration of the 2-azabicyclo[3.3.1]nonane nucleus (D and E rings) by a radical carbocyclization, using an α-carbamoyldichloromethyl radical as a donor. The closure of the C ring by a Bischler-Napieralski cyclization, followed by an epimerization process to gain the axial nitrile 20, and appropriate reduction transformations afforded pentacyclic alcohol 23. This alcohol was converted into either (±)-melinonine-E (1) or (±)-strychnoxanthine (2) by means of a palladium black dehydrogenation of the C ring or a SeO2 oxidation of the corresponding acetate 25, respectively.