Related Experiment Video
Updated: May 13, 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 12-membered to a strained 11-membered ring: first stereoselective total synthesis of (-)-asteriscunolide C
Rodney A Fernandes1, Vijay P Chavan
1Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400 076, Maharashtra, India. rfernand@chem.iitb.ac.in
Abstract:
The first stereoselective total synthesis of (-)-asteriscunolide C has been accomplished in 12 steps in a 16% overall yield. The key step is the conversion of a 12-membered to a strained 11-membered ring with one Z- and two E-double bonds employing a late stage ring-closing metathesis.
Related Concept Videos
Stereoisomerism of Cyclic Compounds
Diels–Alder Reaction Forming Cyclic Products: Stereochemistry
Diels–Alder Reaction Forming Bridged Bicyclic Products: Stereochemistry
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.
[3,3] Sigmatropic Rearrangement of 1,5-Dienes: Cope Rearrangement
[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)
