Novel methodologies for the synthesis of unctionalized pyroglutamates
Pyroglutamates (γ-carboxy-γ-lactams) are nitrogen based heterocyclic compounds that serve as important intermediates in the synthesis of complex heterocyclic molecular frameworks. Many natural products containing fused or spiro heterobicyclic pyroglutamate moieties have been isolated from various terrestrial and marine sources.
For example, lactacystin, omuralide, and cinnabaramides A-G are secondary metabolites isolated from terrestrial strain of Streptomyces sp. Other spirobicyclic β-lactone-γ-lactam based natural products isolated from various strains of Streptomyces sp include compounds such as oxazolomycins, lajollamycin etc
Many of these molecules exhibit potent anti-cancer, anti-microbial, and other important medicinal properties. Although there have been few reports on the synthesis of pyroglutamates in the literature, the development of simple, highly flexible methodologies for the diverse functionalization and stereoselective synthesis of pyroglutamates is highly desirable to expand the scope of these scaffolds.