Synthesis of unstable 4-benzoyl-1,6-anhydro-3-keto-β-D-mannopyranose via stereoselective photobromination of 2,3-isopropylidene-4-benzoyl-1,6-anhydro-β-D-mannopyranose
Jassem G. Mahdi , Hanaa M. Dawoud , Abigail J. Manning , Harvey F. Lieberman , David R. Kelly
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引用次数: 0
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 bromination of the isopropylidene group, which was subsequently eliminated during the aqueous workup. Thus, the aim of this article is to identify the molecular structure of the unstable compound 7.
2,3-异丙基-4-苯甲酰-1,6-无水-β- d -甘露糖立体选择性光溴化合成不稳定的4-苯甲酰-1,6-无水-β- d -甘露糖
1,6-无羟基-β- d -葡萄糖吡喃糖衍生物的立体选择性光溴化发生在外显式h6。然而，4-苯甲酰-2,3-异丙基-1,6-无水-β- d -甘露吡喃糖6的光溴化反应产生了不稳定的4-苯甲酰-1,6-无水-3-酮-β- d -甘露吡喃糖7。C-3的立体选择性氧化机理可归因于C-3的易自由基质子萃取，随后异丙基的溴化，随后在水处理过程中被消除。因此，本文的目的是鉴定不稳定化合物7的分子结构。
期刊介绍：
The Journal of Carbohydrate Chemistry serves as an international forum for research advances involving the chemistry and biology of carbohydrates. The following aspects are considered to fall within the scope of this journal:
-novel synthetic methods involving carbohydrates, oligosaccharides, and glycoconjugates-
the use of chemical methods to address aspects of glycobiology-
spectroscopic and crystallographic structure studies of carbohydrates-
computational and molecular modeling studies-
physicochemical studies involving carbohydrates and the chemistry and biochemistry of carbohydrate polymers.
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