Stereospecificity in ozonide and cross-ozonide formation

Bauld, Nathan L.; Thompson, James A.; Bailey, Philip S.

doi:10.1021/ja01009a026

Cited by 74 publications

(48 citation statements)

References 8 publications

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“…A possible explanation for the non-equilibration of the syn and anti zwitterions can be drawn from a consideration that the ozonide cis-trans ratios are solvent dependent (3,16). Pertinent examples are the results obtained (llg) in the ozonolysis of trans-hexene-3 (0.2 M at -30") in pentane, CH2C1,, and Et20, in addition to the normal and cross-ozonide cis-trans ratios observed (3) in the ozonolysis of cis-and trans-4-methylpentene-2 (1 .…”

Section: Resultsmentioning

confidence: 99%

Quantitative investigation of the ozonolysis reaction. IX. On the mechanism of ozonide formation

Fliszár¹,

Carles²

1969

Can. J. Chem.

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The ozonide cis-trans ratios, for both normal and cross-ozonides, have been examined, in a number of cases, in pentane and in benzene solutions. In benzene, at 25 "C, almost invariant cis-trails ratios are observed, regardless of the geometry and initial concentration of olefin. In pentane, these ratios have been found to depend, both at -78 and 25 "C, on the geometry and the initial concentration of the olefin when 1,2-disubstituted ethylenes with bulky substituents are ozonized. However, the crossozonide cis-trmu ratios obtained from trisubstituted ethylenes do not depend on the initial olefin concentration. A tentative mechanistic proposal is suggested in terms of transitory zwitterion-oletin adducts.

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Section: Resultsmentioning

confidence: 99%

Quantitative investigation of the ozonolysis reaction. IX. On the mechanism of ozonide formation

Fliszár¹,

Carles²

1969

Can. J. Chem.

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“…It has been experimentally shown that SOZ is more stable then POZ [5]. At room temperature SOZ can remain stable from a few hours up to a few days, after that it eventually dissociates into formic acid and aldehyde.…”

Section: Introductionmentioning

confidence: 99%

“…According to this theory the five membered ring of SOZ is in the so called C-O half-chair configuration (see Fig. 2a) [5,6]. The position of substitution depends on the initial conformation of the reactants.…”

Section: Introductionmentioning

confidence: 99%

“…According to Kuczkowski's theory, SOZ is more stable in the O-O half-chair ring conformation (see Fig. 2b) and for the case of the 1-alkene SOZ, cis configuration (also called equatorial ) of aliphatic chain [5][6][7][8] was considered stable. This configuration of the aliphatic chain and five membered ring for propene SOZ were supported by early ab initio calculations [8].…”

Section: Introductionmentioning

confidence: 99%

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Conformational studies of aliphatic secondary ozonides (propene, 1-butene and 1-heptene) by means of FTIR spectroscopy

et al. 2006

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Ozonization reaction of simple alkenes was studied by means of FT infrared absorption gas spectroscopy. The reaction was performed at 95 K in neat films of the reactants. IR absorption spectra of the gaseous products were recorded. The spectra were analyzed combining experimental results with theoretical calculations performed at B3LYP 6-311++G (3df, 3pd) level. We found that among all theoretically predicted conformers of propene secondary ozonide, only one which has the O-O half-chair configuration for the five membered ring and the radical attached in the equatorial position was present in the sample. Samples of 1-butene and 1-heptene secondary ozonides consist from two conformers of very similar energy (ΔH =0.3 kJ/mol). The most stable conformer for both ozonides is the one with O-O half-chair configuration of the five membered ring and the radical attached in equatorial position and the aliphatic chain in gauche position. The second stable conformer has the aliphatic chain in anti position.

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“…To explain different cis-trans ozonide ratios in cross ozonides from cis and trans olefins, a mechanism has been proposed involving a carbonyl -primary ozoilide interaction step (3). Recently, refinements have been added to the Criegee n~echanisrn by advocating the formation of syn and arzti zwitterions which combine stereospecifically with aldehydes or ketones io yield ozonides (4).…”

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confidence: 99%

Reactions of ozonides. VIII. An examination of the possibility of reversible ozonide formation using ¹⁴C labelling

Kerur¹,

Diaper²

1969

Can. J. Chem.

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Carboxyl-14G-10-formyldecanoic acid was made by 14C02 carbonation of 10-undecenylmagnesium bromide and ozonolysis of the product. Attempts were made to equilibrate its methyl ester with CHz / \ @R(CM2)gCOOMe and CH2 GH(CH2)8COOMe in various solvents. Little in-'0-0' corporation of label in the re-isolated ozonide was found, and it was concluded that under normal ozonolysis conditions the formation of ring ozonide is essentially irreversible. Slight incorporation in chloroform is explicable either by reversal of the Criegee n~echanism of ozonide formation or by reversal of the recently suggested regenerative carbonyl -primary ozonide reactions.Canadian Journal of Chemistry, 47, 43 (1969) A recent interest in the mechanism of formation of ozonides from oiefins has been sparled by a close examillation of the stereochemistry of the reaction. The Criegee mechanism (I) accommodates stereospecificity by invoking a solvent cage which must be penetrated in crossozonide formation (2). To explain different cis-trans ozonide ratios in cross ozonides from cis and trans olefins, a mechanism has been proposed involving a carbonyl -primary ozoilide interaction step (3). Recently, refinements have been added to the Criegee n~echanisrn by advocating the formation of syn and arzti zwitterions which combine stereospecifically with aldehydes or ketones io yield ozonides (4).Two schoois have studled ozonide r i~~g formation using isotopic oxygen (36,5,6). Incorporation of the label nil both the ether and peroxid~c oxygens or aliphatic ozo~iides was interpreted to mean simultaneous operation of the Criegee mechanism and a regenerative carbonyl -primary ozonide interaction as shown :In the aromatic 180 study, peroxide irtcorporatlon was very nearly negligible and the label it was pointed out that the same seven-membered appeared in the ether oxygen. This silpports the intermediate can give ether-labelled ozonide by Criegee mechanism, but does not exciude a C-O fi$sion of the primary ozonide as shown interactions of the type shown above, because below rather than 0-0 fission as shown above:Can. J. Chem. Downloaded from www.nrcresearchpress.com by 34.217.195.47 on 05/12/18For personal use only.

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Stereospecificity in ozonide and cross-ozonide formation

Cited by 74 publications

References 8 publications

Quantitative investigation of the ozonolysis reaction. IX. On the mechanism of ozonide formation

Quantitative investigation of the ozonolysis reaction. IX. On the mechanism of ozonide formation

Conformational studies of aliphatic secondary ozonides (propene, 1-butene and 1-heptene) by means of FTIR spectroscopy

Reactions of ozonides. VIII. An examination of the possibility of reversible ozonide formation using ¹⁴C labelling

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Stereospecificity in ozonide and cross-ozonide formation

Cited by 74 publications

References 8 publications

Quantitative investigation of the ozonolysis reaction. IX. On the mechanism of ozonide formation

Quantitative investigation of the ozonolysis reaction. IX. On the mechanism of ozonide formation

Conformational studies of aliphatic secondary ozonides (propene, 1-butene and 1-heptene) by means of FTIR spectroscopy

Reactions of ozonides. VIII. An examination of the possibility of reversible ozonide formation using 14C labelling

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Reactions of ozonides. VIII. An examination of the possibility of reversible ozonide formation using ¹⁴C labelling