Efficient Conversion of a 1,6-Anhydro Chitobiose Derivative into the Corresponding Tetradecyl β-Glycoside Derivative by Means of Participation of a Neighboring Tetradecanamide Group

In the course of our studies on the synthesis of amphiphilic chitoheptaose derivatives carrying binary long hydrocarbon chains at the reducing sugar, tetradecyl 4-O-(2-amino-2-deoxy-β-D-glucopyranosyl)-2-deoxy-2-tetradecanamido-β-D-glucopyranoside was prepared as a model. For general applicability, the 1,6-anhydro-2-deoxy-2-tetradecanamido-β-D-glucopyranosyl moiety was employed as a precursor of the reducing end. Acetolysis of the 1,6-anhydro ring using triethylsilyl triflate gave an oxazoline intermediate as a major product, accompanied by α-glycosyl acetate as a by-product. Immediate treatment of the mixture with 1-tetradecanol and protic acid followed by a separation work-up efficiently led to tetradecyl β-glycoside derivative.