期刊
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
卷 2013, 期 31, 页码 7035-7040出版社
WILEY-V C H VERLAG GMBH
DOI: 10.1002/ejoc.201301116
关键词
Acetals; Carbohydrates; Organocatalysis; Protecting groups; Synthetic methods
资金
- Deanship of Scientific Research (DSR), King Abdulaziz University (KAU) [26-3-1432/HiCi]
- KAU
Methyl glycopyranosides of glucose, galactose, and mannose, their 2,3-di-O-benzyl-protected derivatives, as well as the unprotected sugars react with p-methoxybenzaldehyde dimethyl acetal (3) and with benzaldehyde dimethyl acetal (7) as reagents in the presence of thiourea 1 or squaramide 2 as the organocatalyst to afford regioselectively 4,6-O-arylidenated derivatives 5 and 8. With an excess amount of 3 or 7, diarylidenated derivatives are also obtained. In situ formation of acetals of type 3 and 7 from corresponding aldehydes 10 and 13 in the presence of an orthoester and organocatalyst 1 or 2 can be used to generate 5 and 8 directly from the aldehydes. Some substrates also lead to mixed orthoesters with this procedure. The reaction courses are discussed.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据