Formal synthesis of englerin A utilizing regio- and diastereoselective [4+3] cycloaddition
Shuichi Hagihara1, Kengo Hanaya1, Takeshi Sugai1
1Department of Pharmaceutical Sciences, Faculty of Pharmacy, Keio University, Tokyo, Japan.
Abstract:
Englerin A, a guaiane sesquiterpene isolated from Phyllanthus engleri, showed highly potent and selective growth inhibitory activities against renal cancer cell lines. We synthesized the key tricyclic intermediate from commercially available 2,2-dimethyl-1,3-dioxan-5-one via regio- and diastereoselective [4+3] cycloaddition between the formyl enol silyl ether and the disubstituted furan, in 4.8% total yield over 10 steps.
Related Concept Videos
[4+2] Cycloaddition of Conjugated Dienes: Diels–Alder Reaction
Cycloaddition Reactions: Overview
Diels–Alder Reaction Forming Cyclic Products: Stereochemistry
Diels–Alder Reaction Forming Bridged Bicyclic Products: Stereochemistry
Cyclohexenones via Michael Addition and Aldol Condensation: The Robinson Annulation
Synthesis of α-Substituted Carbonyl Compounds: The Stork Enamine 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)
