86439-85-2Relevant academic research and scientific papers
Influence of Alkyl Chain Ramification on Estradiol Receptor Binding Affinity and Intrinsic Activity of 1,2-Dialkylated 1,2-Bis(4- or 3-hydroxyphenyl)ethane Estrogens and Antiestrogens
Hartmann, Rolf W.
, p. 1668 - 1674 (2007/10/02)
The influence of a symmetrical introduction of CH3 substituents in the α or β positions of the 1,2-dialkyl-1,2-bis(4-hydroxyphenyl)ethene estrogens hexestrol (ethyl, HES) and octestrol (n-propyl, OCES) isopropyl (1), tert-butyl (2), sec-butyl (3), isobut
Thermolabile Hydrocarbons, XVIII. 1-Substituted Neopentyl radicals and their Dimers
Eichin, Karl-Heinz,Beckhaus, Hans-Dieter,Hellmann, Siegried,Fritz, Hans,Peters, Eva-Maria,et al.
, p. 1787 - 1821 (2007/10/02)
Five 3,4-diaryl-2,2,5,5-tetramethylhexanes 1a - e were prepared as pure meso- and DL-isomers.According to the NMR spectra, x-ray analyses for meso- and DL-1e (with an (FB)2E conformation as energy minimum for DL-1e), and force field calculations the diastereomers have distinctly different minimum energy conformations, rotational potentials, and strain enthalpies.Also the activation parameters for the thermal dissociation into 1-arylneopentyl radicals 2 are typically differing.From an entropy discussion it is concluded that sandwich-like diastereomeric radical complexes are formed in these reactions as first intermediates.Their tightness influences ΔS%.The recombinations of the radicals 2 likewise take place stereoselectively.Their substituent effects on the selectivity can also be understood by primary formation of diastereomeric complexes of radical pairs.
