Organische Peroxide, VII. Verhalten von Phenyl‐ und Benzyl‐tert.‐butylhydroperoxiden bei thermischer Zersetzung, Hock‐ und Criegee‐Umlagerung

Abstract

Untersucht werden die thermische Zersetzung sowie die Hock-und die Criegee-Umlagerung von 16 bislang zumeist nicht beschiiebenen Hydroperoxiden (Tab. 3, S. 118) vom Typ des I-Phenyl-(10) und des I-Benzyl-2-methyl-propyl-(2)-hydroperoxids (11). Die Produkte der thermischen Zersetzung entsprechen einem bimolekularen Zerfall der Hydroperoxide zu Alkylperoxy-und Alkoxy-Radikalen sowie deren Folgereaktionen. Bei der Hock-und der Criegee-Umlagerung wird die bekannte synchrone 1.2-Wanderung unter Bildung von Benzylbzw. /3-Phenyl-athylalkoholen sowie deren Estern und Aceton beobachtet. Unter Verwendung von Benzolsulfochloriden als umlagernden Agenzien werden Peroxyketale des Acetons mit dem durch Umlagerung entstandenen Alkohol und dem eingesetzten Hydroperoxid erhalten. Produkte, die sich durch einen elektrophilen Angriff intermediarer Spezies am aromatischen Ring erklaren, entstehen nicht. Organic Peroxides, VIP). Thermal Decomposition, Hock and Criegee Rearrangement of Phenyland Benzyl-tert.-butyl HydroperoxidesThe thermal decomposition and the Hock and the Criegee rearrangements of 16 mostly unknown hydroperoxides (table 3) from the type of 1-phenyl-(10) and of 1-benzyl-2-methyl-2-propyl hydroperoxides (11) are studied.The products of thermal decomposition are in accordance with a bimolecular breakdown of the hydroperoxides resulting in alkylperoxy and alkyloxy radicals and their consecutive reactions. The known synchronous 1,2-rnigration is observed in the Hock and the Criegee rearrangements yielding the corresponding benzyl-and P-phenylethylalcohols respectively, as well as their esters and acetone. Using benzenesulfochlorides for rearrangement, peroxy ketals of acetone, the alcohol resulting from the rearrangement and the starting hydroperoxide are obtained. Products of electrophilic attack of intermediate species on the aromatic ring are not observed.1958 beschrieben Corey und White2) die Umsetzung von 1.3.3-Trimethyl-cyclohexylhydroperoxid (1) mit p-Nitro-benzolsulfochlorid, bei der in 5 -l0proz. Ausbeute

Reductive Cleavage of Organic Peroxides by Iron Salts and Thiols

“…26−29 Peroxide 7 was prepared from the corresponding tertiary bromide following a reported procedure; 2b peroxide 8 was available through methylation of the known tertiary hydroperoxide. 30…”

“…Triacetone triperoxide (TATP, 5 ) and diacetone diperoxide (DADP, 6 ) were prepared through acid-promoted condensations of acetone with hydrogen peroxide − Peroxide 7 was prepared from the corresponding tertiary bromide following a reported procedure; peroxide 8 was available through methylation of the known tertiary hydroperoxide …”

“…The limited reactivity of many peroxides toward reductive or nucleophilic cleavage can be useful in terms of storage, shipping, and the serum stability of peroxide-based antimalarial agents . However, this kinetic stability can create a challenge to decomposing hindered ozonides or peroxides, including peroxide explosives. − The ability of Fe/thiol complexes to catalyze the rapid reduction or disproportionation of all but the most hindered of peroxides under mild conditions could have significant applications for controlled remediation of peroxide-based explosives or unwanted peroxides − or as an approach for activation of peroxides in biological settings …”

“…Caution : TATP and DADP (following entry) are shock-, friction-, heat-, and spark-sensitive high explosives. ,− …”

Epoxidation of strained alkenes catalysed by (1,2-dimethyl-4(1H)pyridinone-3-olate)2MnIIICl

“…Iodosylbenzene and MPPH were prepared by literature methods. 47,48 Limonene 1,2-epoxide was prepared according to Wilkinson et al 49 1-phenyl-cyclopentene, 1-phenyl-cyclohexene and 1-phenyl-cycloheptene were synthesised by Grignard reaction of Bromobenzene on the corresponding cyclic ketone followed by dehydration in toluene with p-toluenesulfonic acid. equivalents were used).…”