AN EFFICIENT ROUTE TO THE ALPHA-METHYL ESTER OF L-GLUTAMIC ACID, AND ITS CONVERSION INTO CIS-5-HYDROXY-L-PIPECOLIC ACID

The treatment of the N-benzyloxycarbonyl alpha-methyl esters of L-glut amine or L-asparagine with tert-butyl nitrite in refluxing acetonitril e results-in selective hydrolysis of the amide group, giving optically pure Z-Glu-OMe (74%) or Z-Asp-OMe (88%); these are versatile chiral b uilding blocks, and an efficient synthesis of cis-5-hydroxy-L pipecoli c acid from Z-Glu-OMe is described.