A Migratory Ether Formation Route to Medium-Sized Sugar Mimetics

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• 作者：Dr. Hao Jiang ; Dr. Li-Ping Xu ; Dr. Yan Fang ; Dr. Zhen-Xing Zhang ; Prof. Dr. Zhen Yang and Prof. Dr. Yong Huang
• 刊名：Angewandte Chemie
• 出版年：2016
• 出版时间：November 7, 2016
• 年：2016
• 卷：128
• 期：46
• 页码：14552-14556
• 全文大小：2343K
• ISSN：1521-3757

文摘

Polyol-substituted cyclic ethers are fundamental building blocks of biomolecules. The position and stereochemistry of multiple hydroxy substituents of cyclic ethers play a central role in their biological function. Current methods for the synthesis of such structures are limited to “naked” ring products with no or few substituents. Here we describe a general route to medium-sized polyol cyclic ethers using a migratory ether formation strategy. In contrast to the common pathway of direct opening of epoxides, Me₃Al was found to promote an unprecedented ether addition reaction, opening a neighboring epoxide. The resulting oxonium intermediate triggers a 1,3-methyl shift to yield 2-deoxyribital products. When the hemiacetal auxiliary is a monosaccharide, the sugar ring is expanded by four atoms to give the corresponding 9- to 11-membered analogues. This method provides an entry into the untapped chemical space of medium-sized sugar mimetics.