Protecting-group-free O-glysosidation using p-toluenesulfonohydrazide and glycosyl chloride donors

详细信息    查看全文

• 作者：Rohan J. Williams ; Caroline E. Paul ; Mark Nitz
• 关键词：Protecting-group-free glycosidation ; Protecting-group-free glycosylation ; N&prime ; -Glycosylsulfonohydrazides ; Glycosyl chlorides
• 刊名：Carbohydrate Research
• 出版年：11 March, 2014
• 年：2014
• 卷：386
• 期：Complete
• 页码：73-77
• 全文大小：800 K

文摘

A range of N鈥?glycosylsulfonohydrazides (GSHs) display good reactivity but poor stereoselectivity in protecting-group-free O-glycosidations when a moderate excess of the model acceptor n-decanol is employed. This stable, readily-accessed class of donor may be more tractable for the glycosylation of non-volatile acceptors than Fischer鈥檚 glycosidation conditions. It is possible to generate unprotected glycosyl chlorides from GSHs in situ. In an effort to find conditions to improve glycosidation stereoselectivity, methanolysis of unprotected glucosyl chloride under halide-ion exchange conditions was examined. Relative to its tetra-O-benzyl analogue, this donor displays moderate, inverted stereoselectivity and a significantly faster reaction rate.