Facile synthesis of 2-C-methyl-d-arabino-γ-1, 4-lactones and mechanism study. Issue 15 (11th April 2018)

• Record Type: Journal Article
• Authors: Lv, Bingqing; Guo, Shuang; Zhu, Fuqiang; Hu, Tianwen; Guo, Qi; Lin, Haixia; Xie, Yuanchao; Shen, Jingshan
• Is Part Of: Tetrahedron letters. Volume 59:Issue 15(2018)
• Page Start: 1473
• Page End: 1475
• Publication Date: 2018-04-11
• Subjects: Nucleoside -- 2-C-Methyl-d-arabino-γ-lactone -- Mechanism -- SN2 reaction -- 18O-labelled DMSO; Chemistry, Organic -- Periodicals; 547.005
• DOI: 10.1016/j.tetlet.2018.03.007
• Languages: English
• ISSNs: 0040-4039

Abstract

Graphical abstract: Highlights: A DMSO-participating reaction mechanism for the synthesis of 2- C -methyl-d -arabino- γ -1, 4-lactones. The mechanism relying on the C2 leaving groups, but not the C3 or C5 protecting groups. A novel approach suitable for the scalable preparation of 3, 5-di- O -benzoyl-2- C -methyl-d -arabino-γ-lactone4a . Abstract: In our previous research on the synthesis of 3, 5-di- O -benzoyl-2- C -methyl-d -arabino-γ-lactone4a, the reaction mechanism of DMSO-mediated configuration inversion of C2 hydroxyl group in the lactone was ambiguous. As a follow-up to this research, we used 18 O-labelled H2 O and DMSO to investigate the mechanism. It was surprisingly discovered that DMSO served as an oxygen donor to stereoselectively displace the leaving group, and was regenerated in the reaction. The protecting groups had no influence on the inversion, but would significantly affect the yield. We also disclosed another approach for the synthesis of4a without using the expensive Tf2 O, which was more suitable for application.