Synthesis of a Peroxime Proliferator Activated Receptor (PPAR) α/γ Agonist via Stereocontrolled Williamson Ether Synthesis and Stereospecific S<sub>N</sub>2 Reaction of <i>S</i>-2-Chloro Propionic Acid with Phenoxides
作者:James A. Aikins、Michael Haurez、John R. Rizzo、Jean-Pierre Van Hoeck、Willy Brione、Jean-Paul Kestemont、Christophe Stevens、Xavier Lemair、Gregory A. Stephenson、Eric Marlot、Mindy Forst、Ioannis N. Houpis
DOI:10.1021/jo050268e
日期:2005.6.1
The stereospecific synthesis of the PPAR alpha/gamma agonist I was accomplished via ethylation of the optically pure tribydroxy derivative 6, itself derived via an enzymatic resolution. The ethylation can be accomplished without epimerization only under strict control of the reaction conditions and the choice of base (sodium tert-amylate), temperature (-30 degrees C), order of addition, and solvent (DMF). The key diastereospecific S(N)2 reaction of the phenol 4 with S-2-chloropropionic acid is best achieved via the sodium phenoxide of 4 derived from Na-0 as the reagent of choice. The structure elucidation and key purification protocols to achieve pharmaceutical purity will also be described.