Synthesis of natural product inspired glycohybrid triazoles

Abstract

This thesis deals with the synthesis and characterization of the natural product derived triazolyl conjugates. Initially, the synthesis of azido-sugars was carried out using commercially available monosaccharides (D-glucose, D-galactose, D-mannose, D-xylose and D-ribose) and disaccharide (D-lactose) as substrates. After successful synthesis and characterization of azido sugars, we next explored three different natural products, namely, andrographolide, anthraquinone and levoglucosan. A novel andrographolide derived terminal alkyne was synthesized and coupled with variety of azido-sugars and polycyclic azides via CuAAC to furnish respective triazolyl derivatives. The synthesized triazolyl derivatives were next explored for their application in metal ion sensing. A second natural product scaffold covered in the thesis is 9,10-anthraquinone. A library of 9,10-anthraquinone derived triazolyl glycoconjugates were synthesized and characterized via modern techniques (NMR, FTIR, HR-MS and Single crystal X-ray analysis). The last objective of the thesis is the synthesis of levoglucosan derived glycoconjugates. The synthesis of these glycoconjugates was carried out using a new co-catalyst (ascorbyl palmitate sodium salt) which can replace the conventional sodium ascorbate in CuAAC reaction. This new co-catalyst for CuAAC reaction was synthesized from nonedible oils. After successful synthesis and characterization of the co-catalyst, we carried out the synthesis of levoglucosan derived glycoconjugates under microwave condition. The new co-catalyst not only proves to be effective in CuAAC reaction but also opens up an arena where utilization of waste can also be explored. newline