Regiochemistry of an ambident cyclic ketene-N,O-acetal nucleophile and its anion toward electrophiles
作者:Yingquan Song、Hondamuni I. De Silva、William P. Henry、Guozhong Ye、Sabornie Chatterjee、Charles U. Pittman
DOI:10.1016/j.tetlet.2011.06.023
日期:2011.8
O-trisbenzoylated 9, and reacted with phenyl chloroformate to give the similar ring-opened carbonic acid 3-[(2-chloro-ethyl)-phenoxycarbonyl-amino]-3-oxo-1-phenyl-propenyl ester phenyl ester, 13. In contrast, ambident anion 2 reacted with benzoyl chloride to give the β,β-bisbenzoylated cyclic ketene-N,O-acetal, 16, and reacted with phenyl chloroformate to give the novel heterocycle 3-(2-hydroxy-ethyl)-6-phenyl-[1
在去质子化反应中形成的五元环状烯酮-N,O-缩醛,2-恶唑烷基-2-亚基-1-苯基乙酮1及其阴离子2是亲核性亲核试剂。通过2-甲基-2-恶唑啉的苯甲酰化合成化合物1,得到开环的N,C,O-三苯甲酰化产物9,然后使用甲醇KOH进行N,O-双脱苯甲酰化。化合物1与苯甲酰氯反应得到N,C,O-三苯甲酰化9,并与氯甲酸苯酯反应得到类似的开环碳酸3-[((2-氯-乙基)-苯氧羰基-氨基] -3-氧代-1-苯基丙烯基苯基酯,13。相反,环境阴离子2与苯甲酰氯反应生成β,β-双苯甲酰化环状烯酮-N,O-缩醛16,然后与氯甲酸苯酯反应生成新型杂环3-(2-羟基-乙基)-6 -苯基-[1,3]恶嗪-2,4-二酮17。