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
The reaction of bicyclic 1,3-diene 1,4-endoperoxides with SnCl2 re-generated the corresponding dienes in 15–70% yield. The efficiency of the deoxygenation depended on the structure of peroxides. The results were compared with those of Fe(II) as well as Pd(O) assisted reactions.
Reactions of cyclic peroxides with aldehydes and ketones catalysed by trimethylsilyl trifluoromethanesulphonate. An efficient synthesis of 1,2,4-trioxanes
作者:Charles W. Jefford、John Boukouvalas、Shigeo Kohmoto
DOI:10.1039/c39840000523
日期:——
Trimethylsilyl trifluoromethanesulphonate is found to be an efficient catalyst for the reaction of 1,4-endoperoxides and 1,2-dioxetanes with aldehydes and ketones to give 1,2,4-trioxanes in high yields.
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
Intramolecular Oxygen Transfer on the Ozonolysis of a Diphenylcyclopentene Derivative
作者:Charles W. Jefford、John Boukouvalas、Danielle Jaggi、Shigeo Kohmoto、G�Rald Bernardinelli
DOI:10.1002/hlca.19860690422
日期:1986.6.18
The ozonolysis of cis-3,4a,7,7a-tetrahydro-3,3-dimethyl-6,7a-diphenylcyclopenta[1,2,4]trioxine (1) in CH2Cl2 at −78° gave the secondary endo ozonide 2 (43% yield) and an acetal 3 (27% yield) derived from O-insertion at the ortho position of the C(7a) phenyl substituent. Both structures were elucidated by X-ray. Repetition of the ozonolysis in MeOH/CH2Cl220:3 at −78° also gave the same two products