Concise synthesis of two trisaccharides related to the cytotoxic triterpenoid saponin isolated from Pithecellobium lucidum
作者:Priya Verma、Balaram Mukhopadhyay
DOI:10.1016/j.carres.2009.08.012
日期:2009.12
Convergent synthesis of two trisaccharidesrelated to the cytotoxictriterpenoidsaponinisolatedfrom Pithecellobium lucidum is reported. The trisaccharides are synthesized in the form of their propargyl glycosides to leave the scope for further glycoconjugate formation through various multi-component reactions. A simple protecting group manipulation is followed using commercially available monosaccharides
La(OTf)3: An Efficient Promoter for Thioglycoside Activation in Conjunction with N-Iodosuccinimide
作者:Balaram Mukhopadhyay、Somnath Mukherjee
DOI:10.1055/s-0030-1259016
日期:2010.12
Use of La(OTf)3 as a Lewis acid promoter for N-iodosuccinimide-mediated activation of thioglycosides is reported. The glycosylation reactions proceeded smoothly with good to excellent yields and stereoselectivity.
Synthesis of Oligosaccharides Related to a Biodynamic Saponin from<i>Calamus Insignis</i>as Their Propargyl Glycosides
作者:Somnath Dasgupta、Balaram Mukhopadhyay
DOI:10.1002/ejoc.200800834
日期:2008.12
The total synthesis of the carbohydrate portion (penta-and tetrasaccharides) of steroidal saponins, isolated fromCalamus insignis, is reported. A simple route is followed, starting from commercially available D-glucose and L-rhamnose, through high-yielding protecting group manipulation strategies. Sulfuric acid immobilized on silica (H2SO4/silica) was used as an effective Bronsted acid source in conjunction