Stereoselective synthesis of enynones via base-catalyzed isomerization of 1,5-disubstituted-2,4-pentadiynyl silyl ethers or their alcohol derivatives
作者:Jingjin Chen、Guoqin Fan、Yuanhong Liu
DOI:10.1039/c0ob00344a
日期:——
1,5-Disubstituted-2,4-pentadiynyl silyl ethers undergo smooth desilylative isomerization to afford cis-enynones as major products with moderate stereoselectivities in the presence of a catalytic amount of KOtBu or DBU. While the isomerization reactions of their alcohol derivatives catalyzed by KOH, KOtBu or NaH take place efficiently to produce trans-enynones with high stereoselectivities. These reactions
1,5-二取代的2,4-戊二炔基甲硅烷基醚经过顺式脱甲硅烷基化异构化反应,以顺式-乙炔酮为主要产物,并在催化量的二甲基甲酰胺存在下,具有中等的立体选择性。KO Ť卜 或者 DBU。而其醇衍生物的异构化反应是通过酸值, KO Ť卜 或者 碳酸氢钠有效地产生具有高立体选择性的反式-乙炔酮。这些反应为合成具有广泛取代基的烯酮提供了方便实用的途径。