A ring-distortion strategy to construct stereochemically complex and structurally diverse compounds from natural products
Related Experiment Video
Updated: May 14, 2026

Efficient Construction of Drug-like Bispirocyclic Scaffolds Via Organocatalytic Cycloadditions of α-Imino γ-Lactones and Alkylidene Pyrazolones
Published on: February 7, 2019
Robert W Huigens1, Karen C Morrison, Robert W Hicklin
1Department of Chemistry, Roger Adams Laboratory, University of Illinois, 600 South Mathews, Urbana, Illinois 61801, USA.
Abstract:
High-throughput screening is the dominant method used to identify lead compounds in drug discovery. As such, the makeup of screening libraries largely dictates the biological targets that can be modulated and the therapeutics that can be developed. Unfortunately, most compound-screening collections consist principally of planar molecules with little structural or stereochemical complexity, compounds that do not offer the arrangement of chemical functionality necessary for the modulation of many drug targets. Here we describe a novel, general and facile strategy for the creation of diverse compounds with high structural and stereochemical complexity using readily available natural products as synthetic starting points. We show through the evaluation of chemical properties (which include fraction of sp(3) carbons, ClogP and the number of stereogenic centres) that these compounds are significantly more complex and diverse than those in standard screening collections, and we give guidelines for the application of this strategy to any suitable natural product.
Related Concept Videos
Diels–Alder Reaction Forming Cyclic Products: Stereochemistry
Diels–Alder Reaction Forming Bridged Bicyclic Products: Stereochemistry
Stereoisomerism of Cyclic Compounds
Photochemical Electrocyclic Reactions: Stereochemistry
Selection Rules: Photochemical Activation
Thermal Electrocyclic Reactions: Stereochemistry
Selection Rules: Thermal Activation
Conjugated systems containing an even number of π-electron pairs undergo a conrotatory ring closure. For example, thermal electrocyclization of (2E,4E)-2,4-hexadiene, a conjugated diene containing two π-electron pairs, gives trans-3,4-dimethylcyclobutene.
[4+2] Cycloaddition of Conjugated Dienes: Diels–Alder Reaction

![Solid-phase Synthesis of [4.4] Spirocyclic Oximes](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F58508.jpg&w=3840&q=50)