Total synthesis of eurypamides, marine cyclic-isodityrosines from the Palauan sponge Microciona eurypa

Total synthesis of eurypamides A, B, and D, , , and , has been successfully accomplished. The Tl(NO3)3 (TTN) oxidation of the halogenated bisphenols, , , , and , effected regio-controlled cyclization to provide the corresponding diaryl ethers, , , , and . This investigation revealed a structural revision of eurypamide A as to possess (2″S,3″R,4″S)-configuration (), along with the spectral data of pure and , which were previously characterized in a mixture.