Phenolic oxidation towards synthesis of bioactive cyclic peptides

点击翻译按钮获取中文摘要

Synthetic studies on bioactive substances including natural products by phenolic oxidation employing anodic and thallium (III) oxidation reactions as key steps, was undertaken in this research project, as follows. (1)Synthesis of eurypamides. A, B, and D was successfully accomplished by the cyclization at the diaryl ether moieties. This result attached with findings of mono-cyclic peptide carrying the inhibitory activity against MRSA. (2)Bromination of germacrene D by bromonium ion electrochemically generated, provide the new bicyclic products, structures of which were spectroscopically determined. (3)The tandem reaction involving anodic oxidation of phenol derivatives, followed by the Lewis acid arrangement, provides heliannuol E, an alleropathogenic substance of sunflower, along with its congeners. This investigation revealed that the selectivity of the arrangement reaction is conducted by stereochemistry and electric character of aromatic substituents. More effective biological activity than that of natural heliannuols, was observed among synthetic intermediates and related products. (4)The electrochemical construction of the spiroisoxazoline derivatives made it possible to synthesize aerhoplysinin-1 and calafianin, spiroisoxazoline-class marine natural products. In the former investigation, the new ring-opening of the isoxazoline to the cyanohydrin was established, and the revision of the reported structure was undertaken. (5)Verbenachalcone, an activator of the nerve-growing factor of plant origin, was successfully synthesized by anodic oxidation of phenol derivatives carrying mixed halogen-substituents, which provided a methoxy diaryl ether moiety.0