Dehydrooligopeptides. X. Useful Synthetic Method for (E)- and (Z)-Isomers of Dehydroaspartic Acids, and Their Δ1,2-Dehydrodipeptides by the Base-Catalyzed β-Elimination

Article abstract of DOI:10.1246/bcsj.61.3265

Various kinds of N-benzyloxycarbonyl (E)- and (Z)-dehydroaspartic acid (Cbz-ΔAsp) derivatives were succesfully synthesized by both a base-catalyzed β-elimination of β-hydroxyaspartic acid esters (HyAsp) via their β-mesyloxy Asp derivatives and several modes of the cleavages of α-(N-Cbz)-aminomaleic acid anhydride.Moreover, for high-yield synthesis of Δ^1,2-dehydrodipeptides (DHP) containing a ΔAsp residue, a similar β-elimination was applied to Δ¹-DHP with C-terminal HyAsp residue.The configuration of all the new ΔAsp derivatives and their Δ^1,2-DHPs were confirmed mainly on the basis of 1H NMR spectral data.