Photocatalytic, site-selective oxidations of carbohydrates
作者:Daniel J. Gorelik、Victoria Dimakos、Timur Adrianov、Mark S. Taylor
DOI:10.1039/d1cc05124e
日期:——
Site-selective oxidations of carbohydrates, employing acridinium photocatalysis and quinuclidine hydrogen atom transfer catalysis, are presented. Protocols have been developed for oxidations of all-equatorial carbohydrates as well as those containing cis-1,2-diols. Site-selectivity reflects the relative rates of hydrogen atom transfer from the carbohydrate C–H bonds, and can be enhanced using a phosphate
C-2 and C-3 oxidation of d-Glc, and C-2 oxidation of d-Gal by pyranose dehydrogenase from Agaricus bisporus
作者:Jindřich Volc、Petr Sedmera、Petr Halada、Věra Přikrylova、Geoffrey Daniel
DOI:10.1016/s0008-6215(98)00151-7
日期:1998.8
The quinone-dependent sugar oxidoreductase, pyranose dehydrogenase purified from the basidiomycete Agaricus bisporus catalyzed C-2 and C-3 oxidation of D-Glc to D-arabino-hexos-2-ulose (2-keto-D-Glc) and, preferentially, D-ribo-hexos-3-ulose (3-keto-D-Glc). The two aldoketoses accumulated only transiently in the reaction mixture being continually converted to the same end-product, D-erythro-hexos-2,3-diulose (2,3-diketo-D-Glc). D-Gal was oxidized by pyranose dehydrogenase and 1,4-benzoquinone exclusively at C-2 to produce D-lyxo-hexos-2-ulose (2-keto-D-Gal). Structures of the enzyme reaction products were deduced from their N,N-diphenylhydrazone derivatives. (C) 1998 Elsevier Science Ltd. All rights reserved.