Related Experiment Video
Updated: Jan 9, 2026

Preparation of Enantiopure Non-Activated Aziridines and Synthesis of Biemamide B, D, and epiallo-Isomuscarine
Published on: June 13, 2022
Accessing Dihydroazepines and Cyclopentanes from Enynyl Ketones
Li Li1, Shiqing Huang2, Yingjian Gong1
1School of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400044, China.
None:
The stereocontrolled construction of polycyclic architectures from linear precursors remains a significant challenge, particularly for medium-sized rings, where strain and conformational flexibility hinder efficient cyclization. Herein, we report a tandem cyclization strategy converting linear precursors to polysubstituted dihydroazepines. The resulting compounds undergo acid-promoted ring contraction to cyclopentanes with five contiguous stereocenters. Overall, this strategy provides a streamlined route to architecturally sterically congested azepine- and cyclopentane-fused dihydrofuran products with a broad substrate scope and functional group tolerance.
More Related Videos
Related Concept Videos
Diels–Alder Reaction Forming Bridged Bicyclic Products: Stereochemistry
Types of Enols and Enolates
[4+2] Cycloaddition of Conjugated Dienes: Diels–Alder Reaction
α-Hydroxy Ketones via Reductive Coupling of Esters: Acyloin Condensation Overview
Dehydration of Aldols to Enones: Acid-Catalyzed Aldol Condensation
Preparation of Epoxides
Epoxides result from alkene oxidation, which can be achieved by a) air, b) peroxy acids, c) hypochlorous acids, and d) halohydrin cyclization.
Epoxidation with Peroxy Acids
Epoxidation of alkenes via oxidation with peroxy acids involves the conversion of a carbon–carbon double bond to an epoxide using the oxidizing agent meta-chloroperoxybenzoic acid, commonly known as MCPBA. Since the O–O bond of peroxy acids is very weak, the addition of electrophilic oxygen of peroxy acids to...

