The Decomposition ofcis-Fused Cyclopenteno-1,2,4-Trioxanes induced by Ferrous Salts and some oxophilic reagents
作者:Charles W. Jefford、France Favarger、Maria Da Gra�a H. Vicente、Yvan Jacquier
DOI:10.1002/hlca.19950780216
日期:1995.3.22
Two cis-fused cyclopenteno-1,2,4-trioxanes, 1a and 1b, were subjected to Zn in AcOH or FeCl2 · 4H2O in MeCN. In the first case, the main course was deoxygenation to give cyclopentanone (18) and the 1,4-diphenyl- or 1,4-bis(4-fluorophenyl)cyclopent-3-ene-1,2-diol 10 (Scheme 5). In the second case, isomerization chiefly occurred resulting in the formation of a dimer 9 of the respective 3,5-diaryl-5-
Synthesis, Structure, and Antimalarial Activity of Some Enantiomerically Pure,<i>cis</i>-fused cyclopenteno-1,2,4-trioxanes
作者:Charles W. Jefford、Shigeo Kohmoto、Danielle Jaggi、Géza Timári、Jean-Claude Rossier、Manyck Rudaz、Olivier Barbuzzi、David Gérard、Ulrich Burger、Philippe Kamalaprija、Jiri Mareda、Gérald Bernardinelli、Ignacio Manzanares、Craig J. Canfield、Suzanne L. Feck、Brain L. Robinson、Wallace Peters
DOI:10.1002/hlca.19950780312
日期:1995.5.10
corresponding alcohols, and conversion to the (1S)-camphanates (Scheme 4), the structures of which are determined by X-ray analysis. The dynamic properties of ent-7 are investigated by NMR spectroscopy and PM3 calculations. Evidence for an easily accessible twist-boat conformation is obtained. The in vitro and in vivo antimalarialactivities of 7, ent-7,8, and ent-8 as well as those of the racemic mixtures are
Lewis acid catalysed rearrangements of unsaturated bicyclic [2.2.n] endoperoxides in the presence of vinyl silanes; access to novel Fenozan BO-7 analogues
作者:Paul M. O’Neill、Sarah L. Rawe、Richard C. Storr、Stephen A. Ward、Gary H. Posner
DOI:10.1016/j.tetlet.2005.03.022
日期:2005.4
Reactions of a series of unsaturated bicyclic [2.2.n] endoperoxides with allyltrimethylsilane in the presence TMSOTf or SnCl4 provides the cis-configured endoperoxides 9a–12. It is proposed that this novel reaction proceeds via attack of the allylsilane on the carbocation derived from heterolytic cleavage of the endoperoxide bridge. The reaction proceeds with a high degree of diastereoselectivity and