Critical Switching of Cyclization Modes of Polyepoxides in Acidic Aqueous Media and Neutral Water: Synthesis and Revised Structure of a Nerolidol‐Type Sesquiterpenoid. (3rd July 2019)

• Record Type: Journal Article
• Authors: Nishikawa, Keisuke; Morita, Kengo; Hashimoto, Subaru; Hoshino, Akihiro; Ikeuchi, Takumi; Kumagai, Momochika; Morimoto, Yoshiki
• Is Part Of: Angewandte Chemie. Volume 131:Number 30(2019)
• Page Start: 10274
• Page End: 10278
• Publication Date: 2019-07-03
• Subjects: Biomimetische Synthese -- Cyclisierungen -- Diastereoselektivität -- Naturstoffe -- Terpenoide; Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.201906039
• Languages: English
• ISSNs: 0044-8249

Abstract

Abstract: Biomimetic epoxide‐opening cascades of polyepoxides enable the efficient and rapid construction of polyether frameworks. Herein, we show that the epoxide‐opening cascade cyclization that affords tetrahydrofuran products in acidic aqueous media produces tetrahydropyran (THP) in neutral water. THP formation proceeded by simply heating polyepoxides in neutral water and followed a different cyclization mode from those observed so far. The novel cascade cyclization in H2 O was applied to the synthesis of a new nerolidol‐type sesquiterpenoid, resulting in revision of the proposed structure and determination of the absolute configuration. Abstract : Die epoxidöffnende Kaskadencyclisierung von Polyepoxiden liefert Tetrahydrofuran(THF)‐Produkte unter sauren Bedingungen und Tetrahydropyran(THP)‐Produkte in pH‐neutralem Wasser. Die THP‐Bildung verläuft durch einfache Erhitzung von Polyepoxiden in pH‐neutralem Wasser und folgt einer unüblichen Art der Cyclisierung.