Highly Efficient Approach to 4-Ethoxy-5,6-dihydro-6,6-disubstituted Pyran-2-ones using a Combinational Lewis Acid-Base System
作者:Jie Liu、Xing Li、Jun Wang、Xiaoming Feng
DOI:10.1002/adsc.200505383
日期:2006.5
The first efficient approach to 5,6-dihydro-6,6-disubstituted pyran-2-ones was successfully achieved from the reaction between commercially available ethyl 3-ethoxybut-2-enoate and ketones in the presence of BF3⋅Et2O, InBr3 and LDA. BF3⋅Et2O and InBr3 were employed as the Lewis acid to activate the ketone and LDA was employed as the Lewis base to activate ethyl 3-ethoxybut-2-enoate. Aromatic, aliphatic
到5,6-二氢-6,6-二取代吡喃-2-酮所述第一有效的方法已成功地从可商购的3- ethoxybut丁-2-烯酸乙酯和酮类之间的反应中的BF存在实现3 ⋅Et 2 ö ,InBr 3和LDA。BF 3· Et 2 O和InBr 3被用作路易斯酸来活化酮,LDA被用作路易斯碱来激活3-乙氧基丁-2-烯酸乙酯。在温和的条件下,芳族,脂肪族和杂环酮以优异的收率(高达99%)转化为相应的含有季碳原子中心的δ-内酯。