An ugi reaction in the total synthesis of (-)-dysibetaine

Abstract

(-)-Dysibetaine has been synthesized in 11 steps from readily available L-malic acid (see scheme). The key step is a unique Ugi 4-center-3-component cyclization reaction, where an ester group acts as the carboxylic acid component. The use of 1,1,1,3,3,3-hexamethyldisilazane as an ammonia equivalent and a specially designed isocyanide leads to an expeditious synthesis. © 2009 Wiley-VCH Verlag GmbH & Co. KGaA.