N-Z-Pro-D-Leu using synchrotron radiation data from a very small crystal

The crystal structure of the neuroactive artificial dipeptide N-­benzyl­oxy­carbonylprolyl-D-leucine, C₁₉H₂₆N₂O₅, was solved using synchrotron radiation data collected on a very small crystal (20 × 20 × 380 [mu]m). The mol­ecules form hydrogen-bonded 2₁ helices. The acid carbonyl group does not participate in strong hydrogen bonds. This is interpreted as a consequence of close-packing requirements.