A chiral C-3-symmetric bowl-shaped cyclohexapeptide (1), composed of anthranilic acid (2-aminobenzoic acid) and a-amino acid in an alternating sequence, was synthesized from 2-nitrobenzoic acid and leucine. The H-1 and C-13 NMR spectra of 1 suggest a chiral C-3-symmetric bowl-shaped structure. Molecular mechanic calculation revealed that the cyclohexapeptide becomes a bowl-shaped structure when all three a-amino acid components have homochiral side chains.
Synthesis and C2-symmetric structure of a cyclotetrapeptide composed of anthranilic acid and leucine
synthesized from 2‐nitrobenzoic acid and leucine. A single‐crystal X‐ray of the compound revealed a C2‐symmetric bowl‐shaped structure. The cyclic compound had a unique hydrogen‐bonding network composed of three‐centered hydrogenbonds and bifurcatedhydrogenbonds between NH and CO of anthranilic residue. The NMR spectra and molecular modeling of 1 also suggested the chiral bowl structure. Chirality