6669-36-9Relevant academic research and scientific papers
Spiro and dispiro 1,2,4-trioxolane antimalarials
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, (2008/06/13)
A means and method for treating malaria, schistosomiasis, and cancer using a spiro or dispiro 1,2,4-trioxolane is described. The preferred 1,2,4-trioxolanes include a spiroadamantane group on one side of the trioxolane group, and a spirocyclohexyl on the
Spiro and dispiro 1,2,4-trioxolane antimalarials
-
, (2008/06/13)
A means and method for treating malaria using a spiro or dispiro 1,2,4-trioxolane is described. The preferred 1,2,4-trioxolanes include a spiroadamantane group on one side of the trioxolane group, and a spirocyclohexyl or spiropiperidyl ring on the other side of the trioxolane group, whereby the spirocyclohexyl ring is preferably functionalized or substituted at the 4-position or a spiropiperidyl ring that is functionalized or substituted at the nitrogen atom. In comparison to artemisinin semisynthetic derivatives, the compounds of this invention are structurally simple, easy to synthesize, non-toxic, and potent against malarial parasites.
Matrix effects in the low-temperature ozonation of ethylene, tetramethylethylene and 1-hexene
Samuni,Haas,Fajgar,Pola
, p. 177 - 201 (2007/10/03)
The ozonation of the title compounds was studied in argon and CO2 matrices at low temperatures (12-80 K). All three were found to react with ozone in a CO2 matrix deposited at low temperature, and having an amorphous structure. The reaction was found to start at 26 K, the temperature at which the matrix undergoes a phase transition. In contrast, only tetramethylethylene (TME) was found to react in an argon matrix, the other two compounds remaining inactive towards ozone up to the softening temperature of argon (~40 K). These results are interpreted as indicating that reaction between olefins and ozone is initiated at low temperatures once the two reactants are free to move to the required configuration. This idea is supported by molecular dynamics simulations on the TME reaction. The infrared spectra of the primary ozonide of TME, as well as of the primary and secondary ozonide of 1-hexene are reported, and compared with quantum chemical calculations.
Environmental effects on the formation of the primary and secondary ozonides of ethylene at cryogenic temperatures
Samuni,Fraenkel,Haas,Fajgar,Pola
, p. 3687 - 3693 (2007/10/03)
Ethylene and ozone were co-deposited in a cryogenic matrix of argon at 15-26 K and of CO2 at 12-20 K. In the argon matrix, no perceptible reaction took place at any temperature below the softening onset of the matrix, while formation of ethylene ozonides (both primary and secondary) was observed at temperatures as low as 25 K in the amorphous CO2 matrix. The ozonides were identified by their infrared spectra, whose assignments were confirmed with the help of an ab initio calculation. The same reaction is imperceptible in a crystalline CO2 matrix deposited at 65 K, becoming observable only at 77 K and higher temperatures. Molecular dynamics simulations carried out for the solid argon host indicate that a highly organized crystalline structure does not allow the motions required for the reactions. These restrictions are apparently less stringent in the amorphous solid CO2, suggesting it as a suitable solvent for the study of reactions having a low activation barrier.
The Ozonolysis of Ethylene. Microwave Spectrum, Molecular Structure, and Dipole Moment of Ethylene Primary Ozonide (1,2,3-Trioxolane)
Gillies, J. Z.,Gillies, C. W.,Suenram, R. D.,Lovas, F. J.
, p. 7991 - 7999 (2007/10/02)
The gas-phase structure of ethylene primary ozonide (CH2CH2OOO) has been determined from millimeter wave spectra of five isotopic species.Partial substitution, rs, parameters for the lowest energy oxygen envelope conformation (Cs symmetry) are r(CC) = 1.546(3) angstroem, r(CO) = 1.417(10) angstroem, r(OO) = 1.453(10) angstroem, r(CHendo) = 1.088(5) angstroem, r(CHexo) = 1.095(5) angstroem, θ(CCO) = 103.9(2) deg, θ(COO) = 102.1(4) deg, θ(OOO) = 100.1(12) deg, and θ(HCH) = 111.6(3) deg.The electric dipole moment of the normal isotopic species is 3.43(4) D.Two vibrational states, 98(6) and 171(18) cm-1 above the ground state, have been assigned to successive excitations of the pseudorotational mode which corresponds to a ring-twisting vibration of the five-membered ring.The barrier to pseudorotation is estimated to be high (greater than 300 to 400 cm-1) in agreement with ab inito MO calculations.Ethylene primary ozonide, dioxirane (CH2OO), formaldehyde, and ethylene secondary ozonide (CH2OCH2OO) are observed as products of the ozone-ethylene reaction in the low-temperature microwave cell. A mechanism of the ozonolysis of ethylene is presented which suggests that the reaction occurs primarily in the condensed phase on the surface of the cell.Microwave techniques utilizing cis- and trans-CHD=CHD show that ozone adds stereospecifically to ethylene in the formation of ethylene primary ozonide.
Infrared Spectrum of the Primary Ozonide of Ethylene in Solid Xenon
Kohlmiller, Christopher K.,Andrews, Lester
, p. 2578 - 2583 (2007/10/02)
Separate Xe/O3 and Xe/C2H4 mixtures were condensed on a CsI window at 50 K and then warmed to 80-100 K.Strong infrared absorption due to the secondary ozonide and weaker bands at 409, 647, 727, 846, 927, 983, and 1214 cm-1 replaced the ethylene and ozone absorptions.The latter new bands agree with earlier solid film and CO2 matrix studies and are assigned to the primary ozonide.Isotopic substitution (16,18O3, 18O3, CH2CD2, C2D4, 13C2H4) provides a sound basis for vibrational assignments.A sextet splitting for the 647-cm-1 antisymmetric O-O-O stretching mode in the 50percent oxygen-18 enriched experiment confirms the primary ozonide structure and directly characterizes the weak O-O-O single bonds.
