Fragmentation of Carbohydrate Anomeric Alkoxy Radicals: A New Synthesis of Chiral 1-Halo-1-iodo Alditols
作者:Concepción C. González、Alan R. Kennedy、Elisa I. León、Concepción Riesco-Fagundo、Ernesto Suárez
DOI:10.1002/chem.200305294
日期:2003.12.5
reaction was achieved by radical fragmentation of the C1bond;C2 bond, triggered by the initially formed anomeric alkoxy radical, and subsequent trapping of the C2-radical by iodine atoms. This methodology is compatible with the stability of the protective groups most frequently used in carbohydrate chemistry. The potential utility of these 1-halo-1-iodo alditols as chiral synthons was evaluated by
D-葡萄糖,D-半乳糖,D-乳糖,L-鼠李糖,D-allo和L-的1,2-氟代醇,1,2-氯代醇,1,2-溴代醇和1,2-碘代醇的处理具有(二乙酰氧基碘)苯/碘体系的碳水化合物的阿拉伯糖,3-脱氧-D-葡萄糖和3,4-二脱氧-D-葡萄糖家族提供了1-氟-1-碘,1-氯-1-碘1 -bromo-1-iodo和1,1-diiodo alditols分别具有出色的收率。通过最初形成的异头烷氧基自由基引发的C1键; C2键的自由基断裂,以及随后的碘原子对C2自由基的捕获,可以实现该反应。该方法与碳水化合物化学中最常用的保护基的稳定性兼容。