An efficient stereoselective synthesis of fully protected (2 S, 4 R)-4-methylpipecolic acid has been developed. The synthesis was achieved by initial asymmetric α-alkylation of glycine with a chiral iodide, affording the linear precursor as a single stereoisomer. Subsequent aldehyde formation using OsO4/NaIO4 followed by immediate intramolecular cyclization afforded an enamine that was then subjected to hydrogenation to give the final compound ...
[Myers, Andrew G.; Yang, Bryant H.; Chen, Hou; McKinstry, Lydia; Kopecky, David J.; Gleason, James L. Journal of the American Chemical Society, 1997 , vol. 119, # 28 p. 6496 - 6511]
