Synthesis of α,ω-differently substituted cyclic ethers from carbohydrates by β-fragmentation of alkoxyl radicals
作者:Alicia Boto、Rosendo Hernández、Ernesto Suárez
DOI:10.1016/s0040-4039(02)00123-5
日期:2002.3
The β-fragmentation of alkoxyl radicals derived from easily available carbohydrates is a mild and efficient procedure to obtain unsymmetrical α,ω-disubstituted cyclic ethers.
衍生自容易获得的碳水化合物的烷氧基的β片段化是获得不对称α,ω-二取代环醚的一种温和而有效的方法。
β-Fragmentation of Primary Alkoxyl Radicals versus Hydrogen Abstraction: Synthesis of Polyols and α,ω-Differently Substituted Cyclic Ethers from Carbohydrates
The beta-fragmentation of primary alkoxyl radicals, described in many cases as low-yielding and plagued by side reactions, can proceed in satisfactory yields using carbohydrate substrates. The only reaction that can compete significantly with the beta-scission is the intramolecular hydrogenabstraction. The ratio of beta-fragmentation to hydrogenabstraction can be varied according to the reaction conditions