Second‐generation total synthesis of the pigment Aurantricholone

Abstract: Our first total synthesis of aurantricholone established its benzotropolone core by the ring-enlargement of a tetralone. Here we describe another total synthesis of aurantricholone. It reaches the benzotropolone core from a known olefin metathesis product via an equally known dibromide, both of which contain a ketoketal moiety. The next transformation - step 9 overall - engaged this motif in a β-elimination of ROH rather than in a hydrolysis under the forcing acidic conditions indispensable in all prior benzotropolone preparations from such an intermediate. In step 10, the Csp2−Br bonds of the elimination product underwent two doubly Z-selective Suzuki couplings with a boronylated O-methyl 4-methylidenetetronate. This gave penta(O-methyl)aurantricholone. Its NMR shifts matched essentially those of a derivative of natural aurantricholone by Steglich et al. Three O−Me bonds were cleaved with BBr3/CH2Cl2 (step 11) and two O−Me bonds with LiBr/DMF (step 12). A 1 : 3 co-crystal of aurantricholone and DMSO allowed for an X-ray structure analysis

Angaben zum Objekt

• Standort: Deutsche Nationalbibliothek Frankfurt am Main
• Umfang: Online-Ressource
• Sprache: Englisch
• Anmerkungen: European journal of organic chemistry. - 26, 42 (2023) , e202300648, ISSN: 1099-0690

Beteiligte, Orts- und Zeitangaben

• Ereignis: Veröffentlichung
• (wo): Freiburg
• (wer): Universität
• (wann): 2023
• Urheber: Koblischek, Philip ; Brückner, Reinhard

Weitere Informationen

• DOI: 10.1002/ejoc.202300648
• URN: urn:nbn:de:bsz:25-freidok-2402991
• Rechteinformation: Open Access; Der Zugriff auf das Objekt ist unbeschränkt möglich.
• Letzte Aktualisierung: 25.03.2025, 13:53 MEZ