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The various methods for the de novo asymmetric synthesis of the pyranose sugars are surveyed in this update of the 2013 Advances in Carbohydrate Chemistry and Biochemistry review. The survey begins with a general overview of the various de novo approaches to carbohydrates and defines the use of asymmetric catalysis for the de novo asymmetric synthesis of pyranoses. Next the application to pyranose-containing oligosaccharides is introduced via the use of a palladium-mediated glycosylation. The application of the diastereoselective palladium-catalyzed glycosylation in conjunction with the Achmatowicz approach towards the synthesis of oligosaccharides is presented. Finally, an alternative diastereoselective palladium-catalyzed glycosylation, followed by ring-closing methathesis to oligosaccharides is reviewed., (Copyright © 2024 Elsevier Inc. All rights are reserved, including those for text and data mining, AI training, and similar technologies.)

The various methods for the de novo asymmetric synthesis of the pyranose sugars are surveyed. The presentation begins with the work of Masamune and Sharpless with the use of the Sharpless asymmetric epoxidation for the synthesis of all eight l-hexoses. The development of other asymmetric reactions and their application for the synthesis of specific hexopyranoses are further discussed. The broad application of the Achmatowicz rearrangement with asymmetric catalysis, for the synthesis of various pyranones and imino sugars, is also presented. Finally, the use of a diastereoselective palladium-catalyzed glycosylation with the Achmatowicz approach for the synthesis of oligosaccharides and applications to medicinal chemistry are discussed., (© 2013 Elsevier Inc. All rights reserved.)

Two known cleistriosides and six known cleistetrosides were synthesized and evaluated for anticancer and antibacterial activity. This study, for the first time, reports anticancer activity and comprehensively the antibacterial activity for these oligosaccharide natural products. In addition, two new unnatural cleistetroside analogues were synthesized and tested. Biological activities for the ten oligosaccharides against B. subtilis were found to range between 4 and >64 µM, and for NCI-H460 human lung cancer epithelial cells between 7.5 and 90.9 µM. Similar activities were found for seven of the oligosaccharides against the NCI panel of 60 cell lines. The degree of acylation and location of the specific acetate groups had significant effects on the anticancer and antibacterial activity of both the cleistriosides and cleistetrosides.