title: An Improved Helferich Method for the α/β-Stereoselective Synthesis of 4-Methylumbelliferyl Glycosides for the Detection of Microorganisms.
abstract: An improved Helferich method is presented. It involves the glycosylation of 4-methyl-umbelliferone with glycosyl acetates in the presence of boron trifluoride etherate combined with triethylamine, pyridine, or 4-dimethylaminopyridine under mild conditions, followed by deprotection to give fluorogenic 4-methylumbelliferyl glycoside substrates. Due to the use of base, the glycosylation reaction proceeds more easily, is uncommonly α- or β-stereoselective, and affords the corresponding products in moderate to excellent yields (51%-94%) under appropriate conditions.
authors.affiliation: Guangzhou Institute of Chemistry, Chinese Academy of Sciences, Guangzhou 510650, China. wxhu7508@163.com.|State Key Laboratory of Applied Microbiology Southern China, Guangdong Institute of Microbiology, Guangzhou 510070, China. wxhu7508@163.com.|Guangdong Open Laboratory of Applied Microbiology, Guangdong Institute of Microbiology, Guangzhou 510070, China. wxhu7508@163.com.|Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Institute of Microbiology, Guangzhou 510070, China. wxhu7508@163.com.|University of Chinese Academy of Sciences, Beijing 100039, China. wxhu7508@163.com.
authors.forename: Xianhu
authors.initials: X
authors.lastname: Wei
authors.affiliation: Guangzhou Institute of Chemistry, Chinese Academy of Sciences, Guangzhou 510650, China. mayanxia880626@163.com.|State Key Laboratory of Applied Microbiology Southern China, Guangdong Institute of Microbiology, Guangzhou 510070, China. mayanxia880626@163.com.|Guangdong Open Laboratory of Applied Microbiology, Guangdong Institute of Microbiology, Guangzhou 510070, China. mayanxia880626@163.com.|Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Institute of Microbiology, Guangzhou 510070, China. mayanxia880626@163.com.|University of Chinese Academy of Sciences, Beijing 100039, China. mayanxia880626@163.com.
authors.forename: Yanxia
authors.initials: Y
authors.lastname: Ma
authors.affiliation: State Key Laboratory of Applied Microbiology Southern China, Guangdong Institute of Microbiology, Guangzhou 510070, China. wuqp203@163.com.|Guangdong Open Laboratory of Applied Microbiology, Guangdong Institute of Microbiology, Guangzhou 510070, China. wuqp203@163.com.|Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Institute of Microbiology, Guangzhou 510070, China. wuqp203@163.com.
authors.forename: Qingping
authors.initials: Q
authors.lastname: Wu
authors.affiliation: State Key Laboratory of Applied Microbiology Southern China, Guangdong Institute of Microbiology, Guangzhou 510070, China. zhangjm926@126.com.|Guangdong Open Laboratory of Applied Microbiology, Guangdong Institute of Microbiology, Guangzhou 510070, China. zhangjm926@126.com.|Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Institute of Microbiology, Guangzhou 510070, China. zhangjm926@126.com.
authors.forename: Jumei
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Guangdong Huankai Microbial Sci. &amp; Tech. Co., Ltd., Guangzhou 510663, China. caizhihe1971@163.com.
authors.forename: Zhihe
authors.initials: Z
authors.lastname: Cai
authors.affiliation: Guangdong Huankai Microbial Sci. &amp; Tech. Co., Ltd., Guangzhou 510663, China. lumianf@163.com.
authors.forename: Mianfei
authors.initials: M
authors.lastname: Lu
mesh_terms: D015761:4-Aminopyridine / Q000031:analogs & derivatives / Q000737:chemistry; D001880:Boranes / Q000737:chemistry; D002384:Catalysis; D005021:Ethylamines / Q000737:chemistry; D006027:Glycosides / Q000138:chemical synthesis*; D006031:Glycosylation; D006923:Hymecromone / Q000031:analogs & derivatives* / Q000138:chemical synthesis; D011725:Pyridines / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: C030561:4-methylumbelliferyl glycosides; D001880:Boranes; D005021:Ethylamines; D006027:Glycosides; D011725:Pyridines; D006923:Hymecromone; C101707:boron trifluoride etherate; D015761:4-Aminopyridine; C023666:pyridine; C003885:4-dimethylaminopyridine; C016162:triethylamine
keywords: 4-methylumbelliferyl glycosides; fluorogenic substrates; glycosyl acetates; peracetyl sugars; stereoselective glycosylation