Boat Conformation of cyclo‐[ L ‐Pro2‐ D ‐Pro]

Conformational studies on small cyclic peptides are particulary informative because such compounds have model character owing to their limited flexibility. In cyclotripeptides made up of three chiral amino acids, the same chirality leads to the crown from, whereas differing chirality should lead to the boat from. This was confirmed for cyclo-[L-Pro2-D-Pro] in solution and in the solid state.