1-Octene ozonide

We have also examined the yields, and for 3-hexene the ozonide cis-ti ans ratio, in the symmetrical ozonides which result from the various reaction conditions used (Table II). Unfortunately, we were not able to get reliable cis-trans ratio determinations for the 4-octene ozonide because of the poor resolution of this pair on the GLPC column. 

Reliable ozonide cis-trans ratios for 4-octene ozonide not yet available. 

Hexene and 4-Octene Ozonide Yields from Various Sources... 

Ozonides and alkoxyhydroperoxides from 1-octene and ethyl 10-undecenoate were isolated by column chromatography and oxidized to acids, RCOOH, using (a) 02 at 95°C.,... 

Procedures. Chromatographic Purification of Ozonization Products. Ozonization products from ethyl 10-undecenoate and 1-octene were chromatographed on silica gel columns (Baker) and eluted with 15 or 25% ether in petroleum ether (b.p., 30°-60°). Fractions were examined by thin-layer chromatography (TLC) on silica gel G Chroma-gram sheet eluted with 40% ether in petroleum ether. For development of ozonide and peroxide spots, 3% KI in 1% aqueous acetic acid spray was better than iodine. The spots (of iodine) faded, but a permanent record was made by Xerox copying. Color of die spots varied from light brown (ozonide) to purple-brown (hydroperoxide), and the rate of development of this color was related to structure (diperoxide > hydroperoxide > ozonide). 2,4-Dinitrophenylhydrazine spray revealed aldehyde spots and also reacted with ozonides and hydroperoxides. Fractions were evaporated at room temperature or below in a rotary evaporator. 

Work on the pyridine-modified ozonization of tetramethylethylene showed that pyridine oxide is not-a product of ozonization (8). Most of the pyridine (— 90% ) remains unchanged during double bond cleavage. Only one mole of acetone, rather than two, is formed for each mole of olefin oxidized. Other work with a disubstituted olefin, trans-4-octene, showed that ozonides are formed in the reaction so that the reaction of pyridine with ozonide to form acid and aldehyde cannot occur (9). An NMR study of trans-4-octene ozonolysis in the presence of pyridine using 1,2-dichloroethane as the solvent shows that aldehyde and hydroxyl-containing material (carboxylic acid, peracid, and other OH species) are formed directly during double bond cleavage. 

Heptene ozonide has been produced by ozonizing mixtures of 3-hexene and 4-octene. The 3-heptene ozonide cis-trans ratio has been determined for a number of sources of this ozonide and found to depend on the stereochemistry of the olefin or pairs of olefins used to generate it. The effect of varying concentrations of added butyraldehyde on the ozonolysis of 3-hexene has been determined. The yields and cis-trans ratios of 3-hexene and 3-heptene ozonides depend on the butyraldehyde concentration. 

The observations of symmetrical cross ozonides from unsymmetrical olefins suggest that unsymmetrical cross ozonides ought to be produced from pairs of symmetrical olefins. Criegee had examined this point earlier (2) and found that no detectable amounts of 3-heptene ozonide were produced when a mixture of 3-hexene and 4-octene was ozonized. Again, this may have been a result of the particular olefin concentrations used. The recent observations that ozonide cis-trans ratios in both cross ozonides (5, 10, 11) and normal ozonides 4-14) can depend on olefin stereochemistry as well as steric factors in the olefin 11) prompted us to reinvestigate the possibility of obtaining unsymmetrical ozonides from pairs of symmetrical olefins. Such an investigation presents an opportunity to examine ozonide cis-trans ratios and yields where several new reaction variables are possible. 

The pure 3-heptene experiments were done on l.OM solutions in pentane. The pure 3-hexene experiments were done on 0.5M solutions in pentane. The mixed hexene and octene experiments were done on pentane solutions which were 0.5M in each olefin. The added aldehyde experiments were done on pentane solutions which were 0.5M in olefin and of varying concentrations of the aldehydes. The ozonides were identified as previously described 11). Ozonide yields were obtained by calibrating the GLPC peak areas with known weights of the ozonides. The elemental analysis of hexene-3 ozonide was previously reported 11). Analyses for heptene-3 and octene-4 ozonide were obtained. 

We have ozonized mixtures of 4-octene and 3-hexene as well as 3-heptene, and examined ozonide cis-trans ratios and yields. For mixtures all possible combinations of the cis and trans isomers of 3-hexene and 4-octene were used, and both the cis and trans isomers of 3-heptene were ozonized. 3-Heptene ozonide was prepared also by ozonizing the... 

The ozonolysis of mixtures of 3-hexene and 4-octene does indeed give 3-heptene ozonide, in addition to the ozonides of 3-hexene and 4-octene. Experiments were then designed to determine the eflFect of olefin geometry in the 3-hexene and 4-octene on the 3-heptene ozonide cis-trans ratio. The yields and cis-trans ratios of 3-heptene ozonide from 10 different sources are given in Table I. In these experiments the pure 3-heptene reactions were carried out at l.OM, while the pure 3-hexene runs were made at 0.5M. Where mixtures of olefins were used, the solution was 0.5M in each olefin. In the olefin-aldehyde experiments the concentrations were 0.5 and 0.25M for olefin and aldehyde, respectively. 

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