Selenium-sulfur analogs. 7. Synthesis and characterization of 4-aralkyl-1,3-selenazoles and -1,3-thiazoles
作者:Robert N. Hanson
DOI:10.1002/jhet.5570210113
日期:1984.1
The diketones 3 and 7 were brominated to give the bromomethyldiketones 4 and 8 which were condensed with selenourea and thiourea to give the corresponding 2-amino-1,3-selenazoles 5a, 9a and 2-amino-1,3-thiazoles 5b, 9b. Reaction with aceticanhydride and benzoic anhydride yielded the 2-acylated derivatives. Biologic evaluation of these compounds indicated some activity as adrenocortical enzyme inhibitors
HANSON, R. N., J. HETEROCYCL. CHEM., 1984, 21, N 1, 57-59
作者:HANSON, R. N.
DOI:——
日期:——
Aromaticity in azlactone anions and its significance for the Erlenmeyer synthesis
作者:Sosale Chandrasekhar、Phaneendrasai Karri
DOI:10.1016/j.tetlet.2006.06.006
日期:2006.8
Azlactone anions—the key intermediates in the classical Erlenmeyersynthesis of amino acids—apparently possess aromatic stabilization, as indicated by the relative rate of base catalyzed deuterium exchange in the following analogs: 1-methyl-2-phenyl-5(4H)-imidazolone > 2-phenyl-5(4H)-oxazolone (azlactone) > 3,3-dimethyl-2-phenyl-4(3H)-pyrrolone. This is paralleled by the relative rate of condensation
Electronic Substituent Effects for the Fine-Tuning of the Regioselectivity in the Diastereoselective Rearrangement of 1,3-Cyclopentanediyl Radical Cations Generated from Tricyclo[3.3.0.0<sup>2,4</sup>]octanes (Housanes) by Chemical Electron Transfer
作者:Waldemar Adam、Thomas Heidenfelder
DOI:10.1021/ja982329e
日期:1998.11.1
tricyclo[3.3.0.02,4]octanes (housanes) 5 through chemicaloxidation with tris(4-bromophenyl)aminium hexachloroantimonate (TBA•+SbCl6-) and shown to afford the regioisomeric olefinic products 6 and 7 on methyl 1,2 migration. A complete reversal in the regioselectivity of the 1,2 shift was observed, which reflects the electronic character of the X substituent at the migration terminus in the radical cation