Synthesis of unstable 4-benzoyl-1,6-anhydro-3-keto-β-D-mannopyranose <i>via</i> stereoselective photobromination of 2,3-isopropylidene-4-benzoyl-1,6-anhydro-β-D-mannopyranose
作者:Jassem G. Mahdi、Hanaa M. Dawoud、Abigail J. Manning、Harvey F. Lieberman、David R. Kelly
DOI:10.1080/07328303.2019.1663204
日期:2020.1.2
Abstract Stereoselective photobromination of 1,6-anhydro-β-D-glucopyranose derivatives occurs at exo-H6. However, photobromination of 4-benzoyl-2,3-isopropylidene-1,6-anhydro-β-D-mannopyranose 6 produced unstable 4-benzoyl-1,6-anhydro-3-keto-β-D-mannopyranose 7. The mechanism of stereoselective oxidation at C-3 could be attributed to the facile radical proton abstraction at C-3, followed by the subsequent
摘要1,6-脱水-β-D-吡喃葡萄糖衍生物的立体选择性光溴化反应在exo-H6处发生。但是,对4-苯甲酰基-2,3-异亚丙基-1,6-脱水-β-D-甘露吡喃糖6的光溴化反应会产生不稳定的4-苯甲酰基-1,6-脱水-β-D-甘露糖吡喃糖7。 C-3处的立体选择性氧化的机理可能归因于C-3处的容易的自由基质子提取,随后是异亚丙基的溴化,随后在水溶液后处理中将其消除。因此,本文的目的是鉴定不稳定化合物7的分子结构。