Synthesis, Acetylation and Silylation of (1E)-2-Diethoxyphosphonylbuta-1,3-dien-1-ols: A Convenient Route to New, Activated Dienylphosphonates
作者:Hashim Al-Badri、Elie About-Jaudet、Jean-Claude Combret、Noël Collignon
DOI:10.1055/s-1995-4122
日期:1995.11
Lithiated carbanions of allylic phosphonates 1 showed strict α-regioselectivity in their reaction with ethyl formate, giving stereoselectively (1E)-2-phosphonodienols 3b and 3d, or a mixture of 3c with its tautomeric aldehyde 4c, or the conjugated aldehyde 5 resulting from the prototropy of the enol 3a. All these compounds, obtained in high yields, were readily transformed into the corresponding stable O-acetylated derivatives 6 or into the O-silylated derivatives 7, whose stability depends on the silicon substituents.
烯丙基膦酸酯 1 的锂化碳负离子在与甲酸乙酯的反应中表现出严格的 α-区域选择性,立体选择性地生成 (1E)-2-膦二烯醇 3b 和 3d,或 3c 与其互变醛 4c 的混合物,或由 5 产生的共轭醛 5烯醇 3a 的质子性。所有这些以高产率获得的化合物很容易转化为相应的稳定的O-乙酰化衍生物6或O-甲硅烷基化衍生物7,其稳定性取决于硅取代基。