The TTN phenolic oxidation, along with the N-protective group of the corres
ponding tripeptide derivatives, was examined to accomplish construction of
a cyclic isodityrosine derivative under solid-phase conditions. The desired
cyclization was effected under the TTN (thallium(III) trinitrate)/NMP-MeOH
conditions to give the corresponding 17-membered ring lactam 12. (C) 2001
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