Tetra-hydro-alstonine.

Area of Science:

• Organic Chemistry
• Crystallography
• Molecular Structure

Background:

• Yohimban alkaloids are a class of indole alkaloids with diverse pharmacological activities.
• Understanding the structure-activity relationship requires detailed analysis of their molecular conformation and crystal packing.

Purpose of the Study:

• To elucidate the molecular conformation and crystal packing of a novel yohimban derivative, methyl (20α)-16,17-didehydro-19α-methyl-18-oxayohimban-16-carboxylate.
• To identify the key intermolecular interactions responsible for crystal cohesion.

Main Methods:

• Single-crystal X-ray diffraction analysis was employed to determine the molecular and crystal structure.
• Analysis of intermolecular interactions, including hydrogen bonds and van der Waals forces, was performed.

Main Results:

• The molecule adopts an L-type conformation.
• Crystal packing is characterized by one N-H⋯π and one C-H⋯π interaction.
• Intermolecular van der Waals contacts, with the shortest O⋯O contact at 3.199(2) Å, ensure crystal cohesion.

Conclusions:

• The study provides a detailed structural characterization of a new yohimban derivative.
• The identified intermolecular interactions offer insights into the solid-state behavior and potential for crystal engineering of related compounds.