Diboron-Catalyzed Regio- and 1,2--α-Stereoselective Glycosylation of -1,2-Diols.

Regio- and 1,2--α-stereoselective glycosylations were investigated using 1,2-anhydroglucose donors and -1,2-diol sugar acceptors in the presence of a diboron catalyst. The reactions proceeded smoothly to provide the corresponding 1,2--α-glycosides with consistently very high stereoselectivity and were regioselectivity controlled by the protecting groups of the acceptor. The present glycosylation method was applied successfully to the efficient synthesis of α-1,3-glucan pentasaccharide.

Synthesis and biological activity of analogs of CPZEN-45, a novel antituberculosis drug.

Analogs of CPZEN-45, which is expected to be a promising new antituberculosis drug that overcomes the shortcomings of caprazamycins, were synthesized and their biological activities were evaluated. The biological activity of analogs 1-3, which converted the anilide portion, and analogs 4 and 5, focusing on the seven-membered ring, were lower than that of CPZEN-45. These results suggest that the inhibitory activity of CPZEN-45 against TagO, an ortholog of WecA, has a strict structural limitation, and it was hoped for elucidation of the mode of action of CPZEN-45 using structural biology in the future.