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 opticallyactive compounds. The variation of ΔG of the thermal ringopening in terms of structural modifications is discussed. The synthesis of the studied compounds, the preparative separation of enantiomers by liquid chromatography
Catalysis by β-Cyclodextrin Hydrate - Synthesis of 2,2-Disubstituted 2<i>H</i>
-Chromenes in Aqueous Medium
作者:Avishek Ghatak、Sagar Khan、Sanjay Bhar
DOI:10.1002/adsc.201500358
日期:2016.2.4
well as propargyl ethers with differently substituted phenols under ambient atmosphere in aqueous medium has been developed using β‐cyclodextrin hydrate as an efficient, recyclable and stable catalyst. This is the first report where β‐cyclodextrin hydrate acted as a catalyst for an organic transformation but β‐cyclodextrin alone failed.