Chiral 2-Aryl-2-methyl-2<i>H</i>-1-benzopyrans: Synthesis, characterization of enantiomers, and barriers to thermal racemization
作者:Guenäelle Harié、André Samat、Robert Guglielmetti、Inge van Parys、Wim Saeyens、Denis de Keukeleire、Klaus Lorenz、Albrecht Mannschreck
DOI:10.1002/hlca.19970800409
日期:1997.6.30
The ease of thermal breaking of the C(sp3)O bond of the 2-aryl-2-methyl-2H-1-benzopyrans 1–9 was evaluated by measuring the free energy (ΔG) of the racemization reaction of optically active compounds. The variation of ΔG of the thermal ring opening in terms of structural modifications is discussed. The synthesis of the studied compounds, the preparative separation of enantiomers by liquid chromatography
的容易性的C(SP的热断裂的3)O 2-芳基-2-甲基-2键ħ -1-苯并吡喃1 - 9通过测量自由能(Δ评价ģ的光学的外消旋化反应的)活性化合物。Δ的变化ģ中的结构修饰方面的热开环进行了讨论。所研究化合物的合成,液相色谱对映体的制备分离,对映体纯度的测定,富集对映体的圆二色性以及通过监测在适当温度下旋光偏振角的减小来测量对映异构体的速率常数被描述。