| Popis: |
The ground-state conformation of a rotationally constrained tryptophan derivative, 3-carboxy-1,2,3,4-tetrahydro-2-carboline, W(1), is determined from single-crystal X-ray diffraction, MM2 calculations, and 1 H NMR coupling constants. The solid-state structure represents the predominant solution conformation. W(1) populates only two minimum-energy conformations in solution, which correspond to the half-chair forms of cyclohexene. The conformers are distinguished mainly by distance of the carboxylate from the indole ring |
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