Total synthesis of gelsemoxonine

Shimokawa, Jun; Harada, Takaaki; Yokoshima, Satoshi; Fukuyama, Tohru

doi:10.1351/PAC-CON-11-10-25

Pure Appl. Chem., 2012, Vol. 84, No. 7, pp. 1643-1650

http://dx.doi.org/10.1351/PAC-CON-11-10-25

Published online 2012-05-02

Total synthesis of gelsemoxonine

Jun Shimokawa, Takaaki Harada, Satoshi Yokoshima and Tohru Fukuyama*

Graduate School of Pharmaceutical Sciences, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan

Abstract: The first total synthesis of gelsemoxonine has been accomplished. A divinylcyclopropane–cycloheptadiene rearrangement of the highly functionalized substrate successfully assembled the spiro-quaternary carbon center connected to the bicyclic seven-membered core structure. A one-pot isomerization reaction of the α,β-unsaturated aldehyde to the saturated ester via a trimethylsilyl cyanide–diazabicycloundecene (TMSCN–DBU) reagent combination allowed a facile and diastereoselective introduction of the latent nitrogen functionality in the unique azetidine moiety.