87742-47-0

Upstream product

• 67-56-1 methanol 
• 78-85-3 2-methylpropenal 
• 769-60-8 2-methyl-1-phenylprop-2-en-1-one 
• 18476-73-8 (3-methylbuta-1,3-dien-2-yl)benzene 
• 98909-21-8 (1-Methoxy-2-methyl-2-propenyl)hydroperoxid 
• 98909-24-1 (1-Methoxy-1-methyl-2-phenyl-2-propenyl)hydroperoxid 
• 98909-25-2 (1-Methoxy-2-methyl-1-phenyl-2-propenyl)hydroperoxid 
• 10027-72-2 methoxymethyl hydroperoxide 
• 72572-79-3 1-methoxy-1-methyl-allyl hydroperoxide 
• 78-94-4 methyl vinyl ketone 
• 513-81-5 2,3-dimethyl-buta-1,3-diene 
• 126-99-8 chloroprene 
• 78-79-5 isoprene 

Relevant academic research and scientific papers

Products and Reaction Routes in the Diozonolysis of 2,3-Dimethyl-1,3-butadiene in Methanol

Treatment of 2,3-dimethyl-1,3-butadiene (1) with 2 molar equiv of ozone in methanol afforded the abnormal products acetic acid (12) and methyl acetate (13), which resulted from cleavage of both the double bonds and the single bond of the conjugated diene system.In model experiments it was shown that the reaction proceeds stepwise by formation of an α,β-unsaturated methoxy hydroperoxide (3) in the first and a α-keto methoxy hydroperoxide (8) in the second ozonolysis step.The latter undergoes spontaneous decomposition at ambient temperatures to give rise to the abnormal cleavage products 12 and 13.This cleavage is accompanied by emission signals in the 1H NMR spectrum which are indicative of the occurrence of acetyl radicals and hence suggest at least a partial radical-type cleavage of the α-keto methoxy hydroperoxide 8.

About the Ozone Cleavage of Chloroprene and of 2-Chloro-3-methyl-1,3-butadiene in Methanol

Monoozonolyses of chloroprene (1a) and of 2-chloro-3-methyl-1,3-butadiene (1b) in methanol occur with more than 90percent at the non-chlorinated double bonds to afford the corresponding α,β-unsaturated oxo compounds 2 with selectivities of 96 and 80percent respectively.The latter subsequently react with methanol, and 2a also with the complementary fragment methoxymethyl hydroperoxide (5).The α,β-unsaturated methoxy hydroperoxides 3 which have also been obtained, are less stable than similarly structured, non-α-chlorinated methoxy hydroperoxides.Diozonolyses of 1a and 1b in methanol afforded in 50-60percent the corresponding α-oxocarboxylates (21) and/or the corresponding ketals.In addition, anomalous products were obtained viz. ca. 15percent of methyl hydroxyacetate (12d) from 1a and 1b, as well as ca. 30percent of dimethyl oxalate (27b) from 1a and ca. 35percent of methyl acetate (13) from 1b.The modes of formation of these products have been postulated according to model reactions.

Diozonolyses of Acyclic Conjugated Dienes in Methanol

In the diozonolyses of isoprene (1a), 2-methyl-3-phenyl-1,3-butadiene (1b), 2,3-diphenyl-1,3-butadiene (26), and 2,3,4,5-tetramethyl-2,4-hexadiene (30) in methanol subsequent reactions of the primary cleavage products afforded abnormal products, which arose from cleavage of both the double bonds and the single bonds of the diene systems.In addition, the diozonolyses of 26 and 30 gave products, in which one of the double bonds of the respective diene system has been epoxidized.The mode of formation of the abnormal cleavage products has been elucidated by the ozonolysis of the intermediate products, viz. of α,β-unsaturated methoxyhydroperoxides and of α,β-unsaturated carbonyl compounds.

Monoozonolyses of Acyclic Conjugated Dienes

Monoozonolyses of isoprene (1a), 2-methyl-3-phenyl-1,3-butadiene (1b), 2,3-diphenyl-1,3-butadiene (25), and 2,3,4,5-tetramethyl-2,4-hexadiene (34) have been examined in pentane and in methanol.The dienes 1a, b and 25 afforded all possible α,β-unsaturated monoozonides and α,β-unsaturated methoxy hydroperoxides, respectively, whereas diene 34 gave no ozonide and no α,β-unsaturated methoxy hydroperoxide.From the dienens 25 and 34, the corresponding monoepoxides have been formed additionally.The results allow some conclusions concerning the regioselectivity of ozone attack at the unsymmetrically substituted dienes 1a, b as well as concerning the cleavage directions of primary ozonides.

Ozonolysis of vinyl chloride in methanol: a convenient entry to methoxymethylhydroperoxide and its chemistry

Ozonolysis of vinyl chloride (7) in methanol at -78 deg C afforded methoxymethylhydroperoxide (10) in high yield along with only trace amounts of methyl formate (14).The former (10) was converted into a mixture of methyl formate (14) as the major and dimethylformal (18) as the minor product by HCl-catalysis in methanol.Reduction of 10 with dimethylsulfide and subsequent treatment with HCl-methanol gave dimethylformal (18).Partial reduction of 10 with a deficient amount of triphenylphosphine gave formaldehyde hemiacetal (19) and methoxymethylhydroxymethylperoxide (20).