A Study on the Photoreaction of 2(5<i>H</i>)-Furanones with Substituted Acetylenes: Evidence for a Mechanistic Reformulation
作者:Ramon Flores、Josep Font、Ramon Alibés、Marta Figueredo
DOI:10.1002/chem.201503888
日期:2016.3.7
The photoreaction of 2(5H)‐furanones with alkynes has been investigated. The complexity of this process is evidenced by the variety of isolated products, which have allowed disclosing interesting mechanistic aspects. When the reaction is performed in acetonitrile under direct excitation, in addition to the primary [2+2] cycloadducts, products derived from an 1,3‐acyl shift rearrangement are also formed
研究了2(5 H)-呋喃酮与炔烃的光反应。分离产品的多样性证明了此过程的复杂性,这些产品允许公开有趣的机械方面。当反应在乙腈中直接激发下进行时,除了伯[2 + 2]环加合物外,还会形成源自1,3-酰基转移重排的产物。对于不对称炔烃,首尾相加的一级加合物的重排会产生新的区域异构体,并且当起始呋喃酮为手性时,这种重排会反转相对的反/正主要环加合物的几何形状。在光敏条件下在丙酮中进行的反应中,从未检测到重排产物,这表明1,3-酰基转移是从β,γ-不饱和内酯的单重激发态S 1发生的。当使用双(三甲基甲硅烷基)乙炔作为炔烃配偶时,主要的光产物是单环双(三甲基甲硅烷基)内酯。