1,1-Dichloroethyl hydroperoxide and 1,1-dichloroethyl peroxide ion as intermediates in the ozonolysis of 2,3-dichloro-2-butene.

On the basis of its spectroscopic and chemical properties, an unstable intermediate previously detected in the ozonolysis of trans-2,3-dichloro-2-butene (1) in inert solvents is reformulated as 1,1-dichloroethyl hydroperoxide (5). Ozonolysis of 1 in ethyl formate saturated with anhydrous HCl leads to high yields of this intermediate. 1,1-Dichloroethyl peroxide ion (10), rather than 5, is believed to be the precursor of acetyl 1,1-dichloroethyl peroxide (8), which is produced in higher yield on ozonolysis of 1 in the presence of tetraalkylammonium chloride

Detection of methyl, hydroxymethyl and hydroxyethyl hydroperoxides in air and precipitation.

It is well established that organic peroxides are formed by OH-radical-induced oxidation of hydrocarbons under atmospheric conditions1. Peroxyacyl nitrates have been known to be constituents of polluted air since the 1950s2,3. In a recent study we have shown that the gas-phase reaction of ozone with a variety of natural and anthropogenic alkenes can contribute to the formation of hydro-philic organic peroxides4. Indications that such peroxides are actually present in the environment have been obtained previously by measurements of the peroxide content of cloudwater and rain. In the absence of a specific analytical method the peroxide content after selective enzymatic destruction of the hydrogen peroxide was taken to be the organic peroxide fraction5-7. In this letter we report the determination by high-performance liquid chroma-tography of methyl (MHP; CH3OOH), hydroxymethyl (HMP; HOCH2OOH) and 1-hydroxyethyl (HEP; CH3CH(OH)OOH) hydroperoxides, in addition to H2O2, and present some preliminary concentration ranges in air and precipitation. The existence of this class of atmospheric trace constituents raises questions about possible adverse biological effects

Another look at the photodechlorination of bromodan.

Contrary to a previous report, there is no solvent-dependent selectivity to either of the double-bond-dechlorinated derivatives when Bromodan is irradiated in hexane or methanol. The 7-dechlorinated derivative formed on photolysis in triethyl amine is debrominated on further irradiation. 13C chemical shifts and long-range CH coupling constants indicate that the structural assignment of the double-bond-dechlorinated isomers must be reversed