Synthesis of 6-methoxy- and 6-chloro-2(1H)-pyridinone acyclo-C-Nucleosides from 2H-1,4-oxazin-2-ones.
作者:Lieven Meerpoel、Gert J. Joly、Georges J. Hoornaert
DOI:10.1016/s0040-4020(01)89920-8
日期:1993.5
Starting from 6-variated 3-methoxy- and 3-chloro-2H-1,4-oxazin-2-ones 4a–e the synthesis of a series of 6-methoxy- and 6-chloro-2(1H)-pyridinone acyclo-C-nucleosides 2a–d and 3a–d was accomplished. Diels-Alder reaction of the oxazinones 4a–e with propargyl bromide yielded the corresponding 3-bromomethylpyridines 5a–e, which underwent easy substitution of the bromine atom with the appropriate nucleophiles
从6-变异的3-甲氧基和3-氯-2H-1,4-恶嗪-2-酮4a-e开始,合成一系列6-甲氧基和6-氯-2(1H)-吡啶酮无环-C-核苷2a–d和3a–d已完成。恶嗪酮4a-e与炔丙基溴的Diels-Alder反应产生相应的3-溴甲基吡啶5a-e,该溴原子容易被适当的亲核试剂取代,从而引入了无环糖部分。在干燥的二甲基甲酰胺中用苯甲醇钠进一步处理,得到苄基保护的C-核苷8a-d和9a-d。8a–d的脱苄基作用在乙醇中使用碳酸锶中毒的钯碳催化剂,并在-78°C下用三氯化硼对9a-d脱保护,可提供稳定的6-甲氧基和6-氯-2(1H)-吡啶酮无环C-核苷2a- d和3a–d。