150780-56-6Relevant academic research and scientific papers
Synthesis, structure, and antimalarial activity of some enantiomerically pure, cis-fused cyclopenteno-1,2,4-trioxanes
Jefford,Kohmoto,Jaggi,Timari,Rossier,Rudaz,Barbuzzi,Gerard,Burger,Kamalaprija,Mareda,Bernardinelli,Manzanares,Canfield,Fleck,Robinson,Peters
, p. 647 - 662 (1995)
Two pairs of enantiomerically pure cis-fused cyclopenteno-1,2,4-trioxanes (7, ent-7 and 8, ent-8) are prepared. Their identities are established by dye-sensitized photo-oxygenation of ent-7 and 8 to the allylic hydroperoxides, reduction to the corresponding alcohols, and conversion to the (1S)-camphanoates, 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 antimalarial activities of 7, ent-7, 8, and ent-8 as well as those of the racemic mixtures are evaluated against Plasmodium falciparum, P. berghei, and P. yoelii. No correlation is observed between configuration and activity. Racemates and pure enantiomers have commensurate activities. The mode of action on the intraerythrocytic parasite is rationalized in terms of close docking by the twist-boat conformer of the trioxane on the surface of a molecule of heme, single-electron transfer to the O-O σ* orbital, and scission to the acetal radical which then irreversibly isomerizes to a C-centered radical, the ultimate lethal agent.
Amplified Asymmetric Dihydroxylation of a Racemic Cyclopentene
Jefford, Charles W.,Timari, Geza
, p. 1501 - 1502 (2007/10/02)
Racemic cyclopenteno-1,2,4-trioxane 1/ent-1 by iterative dihydroxylation with N-methylmorpholine N-oxide in the presence of catalytic amounts of K2OsO4 and (DHQD)2PHAL in aqueous Me2CO at 25 deg C gives essentially enantiomerically pure diols 2 (96percent e.e.) and ent-2 (98percent e.e.) in yields of 31.5 and 43percent, respectively.
The Osmium-Catalyzed Asymmetric Dihydroxylation of cis-Fused Cyclopenteno-1,2,4-trioxanes
Jefford, Charles W.,Misra, Dharmendra,Dishington, Allan P.,Timari, Geza,Rossier, Jean-Claude,Bernardinelli, Gerald
, p. 6275 - 6278 (2007/10/02)
Submission of racemic, cis-fused cyclopenteno-1,2,4-trioxanes (1 and 1-ent) to catalytic amounts of K2OsO4 and (DHQD)2PHAL and 1.2 equivalents of N-methylmorpholine N-oxide in aqueous acetone at 20 deg C (hybrid AD-mix-β) for 2 h gave the (-)-enantiomer,
