Two‐step Synthesis of New γ‐Lactones via Cyclization of 7‐Chloro‐2‐(methoxycarbonyl)‐4‐6‐dimethylocta‐(2E, 4E, 6E)‐trienoic acid. (27th May 2015)

• Record Type: Journal Article
• Authors: Dillenschneider, Jean‐Marc; Dufossé, Laurent; Fouillaud, Mireille; Sutthiwong, Nuthathai; Labia, Roger; Valla, Alain
• Is Part Of: Journal of heterocyclic chemistry. Volume 53:Number 5(2016:Sep.)
• Page Start: 1439
• Page End: 1442
• Publication Date: 2015-05-27
• Subjects: Heterocyclic compounds -- Periodicals; 547.59
• DOI: 10.1002/jhet.2444
• Languages: English
• ISSNs: 0022-152X

Abstract

Abstract : A new rapid synthesis of γ‐lactones, cis fused with a cyclopentenic ring by thermalcyclization of 7‐chloro‐2‐(methoxycarbonyl)‐4‐6‐dimethylocta‐7‐phenyl (or methyl) (2 E, 4 E, 6 E )‐trienoic acids was reported. The key step implicates anintramolecular cyclization to a cyclopentenyl cation, according to an electrocyclic π2s + π2a conrotatory process, published in a recent paper (from the corresponding diacids). We have investigated the thermal behavior of the corresponding half‐esters since; if thecyclization obeys to the proposed mechanism, the diacids, half‐esters must also cyclize in a similar manner.Saponification of these led to γ‐dilactones via intermediary cyclopropanes. Mechanistic pathways were investigated. Abstract :