Fmoc-OASUD: A new reagent for the preparation of Fmoc-amino acids free from impurities resulting from Lossen rearrangement. Issue 37 (14th September 2016)

• Record Type: Journal Article
• Authors: Rao, B. Leela Maheswara; Nowshuddin, Shaik; Jha, Anjali; Divi, Murali K.; Rao, M.N.A.
• Is Part Of: Tetrahedron letters. Volume 57:Issue 37(2016)
• Page Start: 4220
• Page End: 4223
• Publication Date: 2016-09-14
• Subjects: Fmoc amino acids -- OH-ASUD -- Fmoc-OASUD -- Dipeptide -- Fmoc-gabapentin -- Lossen rearrangement; Chemistry, Organic -- Periodicals; 547.005
• DOI: 10.1016/j.tetlet.2016.08.015
• Languages: English
• ISSNs: 0040-4039

Abstract

Graphical abstract: Highlights: Fmoc-OASUD is a new reagent for the synthesis of Fmoc-amino acids. Synthesized Fmoc-amino acids are free from impurities due to Lossen rearrangement. No racemization is observed during the reaction. The reagent gives Fmoc-amino acids in high yields and purity. The reagent is a stable crystalline solid which can be stored for long time. Abstract: A new reagent, 9-fluorenylmethoxy-carbonyl- N -hydroxy-3-azaspiro[5, 5]undecane-2, 4-dione ester (Fmoc-OASUD) for the preparation of Fmoc-amino acids is described. The Fmoc-OASUD reacts with amino acids at room temperature in the presence of a base and gives Fmoc-amino acids in high yields and purity. The Fmoc-amino acids prepared using Fmoc-OASUD are free from impurities due to Lossen rearrangement, which are generally present when Fmoc-OSu is used. This is mainly because of the higher stability of Fmoc-OASUD compared to Fmoc-OSu.