3-Methoxy-1,2,4-trioxolane

Methoxy-3 -methyl-5,6-benzo-6H-1,2-dioxin, 3313 3-Methoxy-4-methyl-5,6-benzo-6 f-l,2-dioxin, 3314 l-(c/5-Methoxyvinyl)-l,4-endoperoxy-2,5-cyclohexadiene, 3153 Methyltrifluoromethyldioxirane, 1102 3-Methyl-l,2,4-trioxolane, 1235... 

The rotational spectra of 3-methoxy-l,2,4-trioxolane (281) and 15 isotopomers containing H, and 0 point to a preferred conformation for both the ring and the methyl group and to other structural features. The C(3) atom is bonded to three oxygen atoms, for which the C—OMe bond distance is short (137.7 pm) as compared to C—(141.1 pm)... 

Ozonolysis of (E) and (Z)-l,2-dimethoxyethene at —41 °C in the presence of acetaldehyde produced mixtures of (E)- and (Z)-3-methyl-5-methoxy-l,2,4-trioxolane, and in the presence of isobutyraldehyde mixtures of (/, )- and (Z)-3-isopropyl-5-methoxy-l,2,4-trioxolane. Ozonolysis of vinyl acetate affords 3-acetoxy-l,2,4-trioxolane and 3-acetoxy-1,2-dioxolane in 34% and 51% yields, respectively, in agreement with Criegee s mechanism <1990JOC1120>. 

In the Criegee proposals the initial product is stipulated to have a 1,2,3-trioxolane structure (I) which is also known as a molozonide structure. This undergoes a concerted decomposition to give a zwit-terion (II) and a carbonyl compound (III). The decomposition products (II) and (III) in most cases recombine to give the normal ozonide (IV). Other possible reactions include dimerization of the zwitterion to yield a diperoxide (V) or a higher peroxide (VI) whilst in the presence of methanol as a reactive solvent a methoxy-hydroperoxide (VII) may be produced. 

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