Related Experiment Video
Updated: Jul 12, 2026

Efficient Construction of Drug-like Bispirocyclic Scaffolds Via Organocatalytic Cycloadditions of α-Imino γ-Lactones and Alkylidene Pyrazolones
Published on: February 7, 2019
A Dipolar Cycloaddition Approach Toward the Kopsifoline Alkaloid Framework
Xuechuan Hong1, Stefan France, Albert Padwa
1Department of Chemistry, Emory University, Atlanta, GA 30322, USA.
Abstract:
Using a metal-catalyzed domino reaction as the key step, the heterocyclic skeleton of the kopsifoline alkaloid family was constructed by a 1,3-dipolar cycloaddition of a carbonyl ylide dipole derived from a Rh(II)-catalyzed reaction of a diazo ketoester across the indole pi-bond. Ring opening of the resulting 1,3-dipolar cycloadduct followed by a reductive dehydroxylation step resulted in the formation of a critical silyl enol ether necessary for the final F-ring closure of the kopsifoline skeleton.
Related Concept Videos
Cycloaddition Reactions: Overview
Cycloaddition Reactions: MO Requirements for Thermal Activation
Cyclohexenones via Michael Addition and Aldol Condensation: The Robinson Annulation
[4+2] Cycloaddition of Conjugated Dienes: Diels–Alder Reaction
[3,3] Sigmatropic Rearrangement of 1,5-Dienes: Cope Rearrangement
Vicinal Diols via Reductive Coupling of Aldehydes or Ketones: Pinacol Coupling Overview
![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)
