Über ein polymeres 2,3‐dimethylbutadienperoxyd

Abstract

Bei der Autoxydation von 2,3-Dimethylbutadien entsteht ein polymeres Peroxyd, das Lich zumindest vorwiegend dur& alternierende 1,2-Mis&polymerisation des Diens mit molekularem Sauerstoff bildet. Durch theimischc Zersetzung des polymeren Peroxyds in Suspension oder P erdunnnng wurden als Bruchstucke Formaldehyd nnd Isopropenylrnethylketon isoliert und identifiriert. Ein monomeres Dimethylbutadienperoxyd wurde nicht heobachtet. S U M M A R Y :The autoxydation of 2,3-dimethylbutadien yields a polymer peroxyd. Dimethylbutadien and oxygen are found to be linked by 1,Zcopolymerisation mainly. Thermal decom. position of the polymer peroxyd in suspension o r dilution delivers formaldehyd and isopropenylmethylketon. Monomeric rlimethylbutadienperoxyd could not be isolated.

Stereoisomeric 2,5‐Dimethyl‐2,3:4,5‐dioxidohexanes as the Main Products of the Pyrolysis of Polymeric 2,5‐Dimethyl‐2,4‐hexadiene Peroxide

“…Using this value, the enthalpy of formation of solid OC(OH)2 is calculated t o be AHf = -155 +-10 kcal/ mole. This value is in good agreement with the enthalpy of formation calculated by the increments method [7] and estimated from the thermochemical data for carbonates [5,8] and trithiocarbonates [8,9].…”

“…Both isomers have characteristic infrared absorptions [4]: the epoxide bands of (2) are at 1237, 899, and 802 cm-1; those of (3) are at 1241, 897, and 810 cm-1 [5]. Chemical proof of the structures of (2) and (3) is supplied by reduction with LiAIH4 to give (5), and by hydrolysis with acid to give the stereoisomeric tetrahydrofuran-2,3-diols; here (2) yields the cis-form (6), and (3) leads to the trans-compound (7) [61.…”

“…80%The formation of acetone and p-methylcrotonaldehyde can be explained by cleavage of 1,2-peroxo-linked structures (B)[7]. Since the amount of acetone formed is 5 %, it can be concluded that the ratio of C~H 1 4 0 2 units in ( I ) with a 1,4-peroxo structure (A) t o units with a 1,2-peroxo link (B) is about 7This observation also explains the diminished thymine dimerization in single-stranded DNA with ethylene glycol as solvent [21.…”

Composition of Gum in Cracked Naphtha

“…The oxidation of reactive olefins is known to be important in their deterioration (76, 79). Previous studies indicate that an acyclic conjugated diene may be representative of the cracked-gasoline component that undergoes autoxidative deterioration (6,8,9). Others have considered the reaction (7 7) of diene, mercaptan, and oxygen to be a predominant cause of gum formation in heavier fuels (24).…”

The Crystal Structure of a Phosphacyanine

“…The formation of acetone and p-methylcrotonaldehyde can be explained by cleavage of 1,2-peroxo-linked structures (B) [7]. Since the amount of acetone formed is 5 %, it can be concluded that the ratio of C~H …”