Stereoselective synthesis of conformationally restricted analogues of aspartic and glutamic acids front endocyclic enecarbamates

Article abstract of DOI:10.1016/S0040-4039(97)00238-4

The stereoselective synthesis of cyclic amino acids incorporating the care framework of aspartic acid and glutamic acids were accomplished from a common intermediate. Oxidative cleavage of an aza-bicyclic-dichlorocyclobutanone/pentanone with Me₂CuLi/Ac₂O followed by ozonolysis furnished the amino acid derivatives in good overall yields in a three-step sequence. This protocol was also applied to the synthesis of a cis-β-amino acid and to the enantioselective construction of a chimeric amino acid incorporating the basic skeleton of four different naturally occurring amino acids into a single structure.