Crystal structure of N-{N-[N-(tert-but-oxy-carbon-yl)-l-α-aspart-yl]-l-α-aspart-yl}-l-α-aspartic acid 14,24,34-trimethyl ester 31-2-oxo-2-phenyl-ethyl ester {Boc-[Asp(OMe)]3-OPac}.
In the title homotripeptide {Boc-[Asp(OMe)]3-OPac}, C28H37N3O13, all peptide bonds adopt an s-trans conformation with respect to the N-H and C=O groups. In the crystal, N-H⋯O hydrogen bonds result in an infinite parallel β-sheet structure running along the b-axis direction. The Boc protecting group at the N-terminus of the peptide is disordered over two sites with occupancy factors of 0.504 (5) and 0.496 (5).