An efficient synthesis of novel L-rhamnose based non-ionic surfactants under controlled microwave irradiation

作者：Hricoviniova Zuzana^*; Hricovini Milos

来源：Tetrahedron: Asymmetry , 2014, 25(13-14): 1008-1014.

DOI：10.1016/j.tetasy.2014.05.012

The scope and limitations of microwave-assisted glycosylation for the preparation of various alkyl L-rhamnoside amphiphiles were investigated. Straightforward coupling of hydrophilic unprotected sugar and hydrophobic high molecular weight alcohols, in the presence of p-toluenesulfonic acid as a promoter, yielded structurally different compounds in very good yields (37-87%). A homologous series including 17 examples of alkyl alpha-L-rhamnoside amphiphiles varying in chain structure (C-4-C-20) is reported. The structures of the new derivatives were determined by NMR spectroscopy and quantum chemical calculations. Molecular geometry optimizations of different ring forms (C-1(4) and C-4(1)) and anomeric configurations were carried out using DFT calculations. Herein we demonstrate the advantages of microwave irradiation for the preparation of a broad variety of linear and branched-chain alkyl alpha-L-rhamnosides. The application of this approach to the synthesis of new natural non-ionic surfactants makes this method attractive because of their potential use in biomedical and pharmaceutical chemistry.

• 出版日期2014-7-31