Alkynes From Furans: A General Fragmentation Method Applied to the Synthesis of the Proposed Structure of Aglatomin B. Issue 14 (28th February 2018)

• Record Type: Journal Article
• Authors: Deng, Jiachen; Wu, Jingjing; Tian, Hailong; Bao, Jiajing; Shi, Yong; Tian, Weisheng; Gui, Jinghan
• Is Part Of: Angewandte Chemie international edition. Volume 57:Issue 14(2018)
• Page Start: 3617
• Page End: 3621
• Publication Date: 2018-02-28
• Subjects: alkynes -- cycloaddition -- furans -- natural products -- singlet oxygen; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201712365
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: Furans are versatile synthons in organic chemistry. Described is a general method for transforming furans into alkynes by dual C−C double‐bond cleavage. The reaction is proposed to proceed by sequential [4+2] cycloaddition between furan and singlet oxygen and a formal retro‐(3+2) fragmentation of the endoperoxide intermediate. A wide array of furans, including those derived from sapogenins, are amenable to this reaction, thus providing the corresponding alkynoic acids in up to 88 % yields. The synthetic utility was demonstrated by a seven‐step synthesis of the proposed structure of a pregnane natural product, aglatomin B, from a known intermediate. Abstract : A general fragmentation method that transforms furans into alkynes, by dual C−C double‐bond cleavage, is described. The reaction is proposed to proceed by sequential [4+2] cycloaddition between furan and singlet oxygen, and a formal retro‐(3+2) fragmentation of the endoperoxide intermediate. The synthetic utility was demonstrated by a seven‐step synthesis of the proposed structure of aglatomin B.