An Ugi Reaction in the Total Synthesis of (−)-Dysibetaine
作者:Jerry Isaacson、Yoshihisa Kobayashi
DOI:10.1002/anie.200805709
日期:2009.2.23
(−)‐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.