Phenserine synthesis

Yu QS, HoUoway HH, Flippen Anderson JL, et ai. Methyl analogues of the experimental Alzheimer drug phenserine. Synthesis and structure/activity relationships for acetyl- and butyrylchoHnesterase inhibitory action, / Chem 44 4062 071,2001. 

Synthesis of Heterocyclic Natural Products (-)-Ephedradine A, (-)-a-Tocopherol, (-)-Lepadin D, and (-)-Phenserine... 

Brossi A, Pei X-F and Greig NH (1996) Phenserine, a novel anticholinesterase related to physostigmine total synthesis and biological properties. AustJ Chem 49, 171-181. 

Yu Q, Holloway HW, Utsuki T, Brossi A, Greig NH (1999) Synthesis of novel phenserine-based-selective inhibitors of butyrylcholinesterase for Alzheimer s disease. J Med Chem 42 1855-1861... 

Also, bis-alkylthiocarbene undergoes the [4+1] cycloaddition reaction with a suitably substituted indol isocyanate to give the [4+1] cycloadduct in 72 % yield. This approach was utilized in the total synthesis of (+) phenserin . Numerous examples of vinyl isocyanates, generated from the corresponding carbonyl azides, in the presence of bis-alkylthiocarbene precursors afford the [4+1] cycloadducts, often in high yields . ... 

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