DAIB/TEMPO mediated synthesis of anomeric lactones from anomeric hydroxides. Issue 20 (17th May 2017)

• Record Type: Journal Article
• Authors: Chatterjee, Debnath; Halder, Tanmoy; Pathak, Navendu P.; Paul, Abhijit; Rajkamal, ; Yadav, Somnath
• Is Part Of: Tetrahedron letters. Volume 58:Issue 20(2017)
• Page Start: 1943
• Page End: 1946
• Publication Date: 2017-05-17
• Subjects: Sugar lactone -- Oxidation -- One-pot -- Thioglycoside -- Carbohydrate building blocks; Chemistry, Organic -- Periodicals; 547.005
• DOI: 10.1016/j.tetlet.2017.04.019
• Languages: English
• ISSNs: 0040-4039

Abstract

Graphical abstract: Highlights: Avoids metal based oxidants and uses stoichiometric non-metal ones. High yields (85–95%) of the lactones achieved. Several protecting groups used in carbohydrate syntheses tolerated. Advantages of present method demonstrated by comparison with previous methods. Sequential conversion of thioglycosides to lactones via lactols demonstrated. Abstract: Anomeric sugar lactones are important intermediates for the synthesis of C-glycosides, carbasugars and iminosugars. Herein we present a facile synthesis of anomeric sugar lactones via the DAIB/TEMPO oxidation of anomeric hydroxides. The reactions are very efficient providing the lactones in 2–4 h in almost quantitative yields. The reaction conditions tolerate several common protecting groups used in carbohydrate synthesis. The advantages of the present methodology over previously reported non-metal based methods have also been demonstrated through head to head comparisons. Finally, we have applied the reaction for the sequential conversion of anomeric thioglycosides to the lactones through sequential reactions with NBS followed by the oxidation with DAIB/TEMPO.