Terpene and Steroid Alkynyl Peroxides

A method was developed for preparation of alkynyl peroxides from terpene and steroid aldehydes and ketones by reaction of lithium peroxyacetylides with the corresponding aldehydes and ketones followed by treating the intermediate lithium alcoholates with acyl chlorides.     

Formation and Degradation of Polymeric Peroxides

An attempt has been made to bring the literature on polymeric peroxides together from all angles in order to present a comprehensive picture about them. Both polyperoxides, where the peroxide group has been attached to the main chain, and polymeric hydroperoxides, where the peroxide group is present as a side chain, have been considered. Various aspects such as formation, thermal decomposition characteristics, photodecomposition, and analysis of peroxides have been discussed.     

Perfluoro Alkyl Hypofluorites and Peroxides Revisited

A more convenient synthesis of the perfluoro alkyl hypofluorite (F₃C)₃COF as well as the hitherto unknown (C₂F₅)(F₃C)₂COF compound is reported. Both hypofluorites can be prepared by use of the corresponding tertiary alcohols R^FOH and elemental fluorine in the presence of CsF. An appropriate access to these highly reactive hypofluorites is crucial. The hypofluorites are then transferred into their corresponding perfluoro bisalkyl peroxides R^FOOR^F [R^F=(F₃C)₃C, (C₂F₅)(F₃C)₂C] by treatment with partially fluorinated silver wool. NMR, gas-phase infrared, and solid-state Raman spectra of the perfluoro bisalkyl peroxides are presented and their chemical properties are discussed.     

Synthesis and Structure of Organoantimony Peroxides

Organoantimony peroxides (Ar₂SbO)₄(O₂)₂ (Ar = Ph, p-Tol) were synthesized by oxidation of triarylantimony with hydrogen peroxide in the presence of nitrosophenol or 4-chlorophenol in an ether solution. X-ray diffraction analysis of peroxides obtained revealed that four antimony atoms have octahedral coordination and are connected via bridging oxygen atoms and two peroxide groups. The C–Sb, Sb–O_br, Sb–OO, and O–O distances are equal to 2.106–2.127, 1.958–1.974, 2.202–2.246, 1.471, 1.470 Å (Ar = Ph) and 2.086–2.139, 1.932–1.983, 2.215–2.289, 1.445–1.466 Å (Ar = p-Tol).     

RAMAN Spectra of Peroxides

The RAMAN spectra of solid polycristalline samples of peroxides of alkali metals, alkaline earths, and two group II transition metals have been measured. The O? O stretch vibration produces an intense band in the expected frequency region of 750 to 850 cm^?1. The observation of a weak band at 815 cm^?1 indicates the existence of BeO₂. Frequency shifts in the hydrates of alkali and alkaline earth peroxides support different water association.     

Peroxides of higher aliphatic ethers

The oxidation of higher aliphatic ethers with oxygen at 50° yields two peroxides as the main oxidation products for each ether, namely a dihydroperoxy-dialkyl ether and a dihydroperoxy-dialkyl peroxide. The mass spectra of these compounds are recorded and the main fragmentation pattern is discussed.     

Chemoselective Hydrogenation of Unsaturated Peroxides

Chemoselective hydrogenation of unsaturated monoperoxyketals provides new methodology for the synthesis of saturated and allyl hydroperoxides.     

No Fear of Perfluorinated Peroxides: Syntheses and Solid‐State Structures of Surprisingly Inert Perfluoroalkyl Peroxides

We report on the solid‐state structures of bis(nonafluoro‐tert‐butyl) peroxide [(F₃C)₃CO]₂ and bis(undecafluoro‐2‐methyl‐2‐butyl) peroxide [(C₂F₅)(F₃C)₂CO]₂. These peroxides were prepared from the corresponding hypofluorites and fluorinated silver wool. The solid‐state structures obtained after in situ crystallisation show unusual COOC dihedral angles of 180°, as well as elongated O?O bonds because of the bulky perfluorinated alkyl groups. The perfluorinated alkyl peroxides are insensitive to both impact (>40 J) and friction (>360 N), and resistant towards mineral acids (HX; X=F, Cl, Br) and elemental halogens (X₂). Ferrocene is oxidized by [(F₃C)₃CO]₂ to [Fe^IIICp₂][OC(CF₃)₃].     

二酰基过氧化物的激光拉曼光谱表征

合成了全氟和其它对位、间位取代的共10种过氧化苯甲酰，测定了它们的固体和溶液（溶剂为F113，CCl2FCClF2)的激光拉曼光谱，首次发现这类化合物中高度对称的过氧键有较强的特征谱带，即vo-o在850至899cm^-1之间，并随取代基不同而呈现规律变化。苯环上的供电子取代基使vo-o移向低波数，而吸电子基则使vo-o移向高波数，由此确认拉曼光谱是一种鉴定对称过氧化键的有效手段。本文还用相关分析的方法探讨了影响这类酰基过氧化物拉曼特征频率vc-o和vo-o的结构因素，表明极性效应是影响vc-o的主要因素，而影响vo-o的情况则比较复杂。     

Epoxides,Hydroperoxides and Peroxides in Air Pollution

A major source of air pollutants in urban areas is automobile exhaust. Olefins constitute a substantial proportion of the chemicals emitted by this source. Olefins undergo autoxidation and photochemical oxidation in air to hydroperoxides, peroxides, epoxides and other oxygenated aliphatics, frequently of low molecular weight. Long-term carcinogenicity assays of these compounds in mice and rats by various routes of administration have shown that some of these compounds are carcinogenic. Hence, their detection and elimination as air pollutants should be vigorously pursued. This report describes the current status of air pollution research on these compounds, their carcinogenicity, structure-activity relationships and areas which deserve attention in future research. Oxidation products of aromatic hydrocarbon pollutants are also important and will be described.     

Serendipitous Discovery of Peptide Dialkyl Peroxides

In an attempt to synthesize a homologous series of peptide peresters, we investigated the reaction of the oxazol‐5(4H)‐ones of Pht‐(Aib)_n‐OH (n=2–8) and tert‐butyl hydroperoxide in the presence of 4‐(dimethylamino)pyridine. Unexpectedly, the major product isolated in each case proved to be the peptide dialkyl peroxide. This novel class of peptide derivatives was characterized by FT‐IR, ¹H‐NMR, MS, cyclic voltammetry, and X‐ray diffraction. On the basis of the experimental data, a plausible mechanism is proposed for this reaction.     

两个单环有机过氧化物的合成

报道了两个新的环状有机过氧化物. 在1,2-二氧六环化合物的合成中, 首次探讨了利用对三取代碳—碳双键的分子内Michael加成来完成过氧环环合的可能性. 在1,2-二氧七环的合成中由于无法利用Michael加成来完成七元过氧环环合, 采用了汞离子媒介的反应来实现七元过氧环的构建.     

Acetylenic Peroxides Derived from 4,4'-Biphenyldicarboxylic Acids

Lithium peroxyacetylides were reacted with Paraform to obtain lithium peroxyalcoholates. The latter react with 4,4'-biphenyldicarboxylic and 2,2'-sulfonyl-4,4'-biphenyldicarboxylic dichlorides, yielding peroxy-containing esters. Lithium peroxyacetylides react with 4,4'-biphenyldicarboxylic and 2-methoxy- and 2,2'-sulfonyl-4,4'-biphenyldicarboxylic acids to form acetylenic biphenyldihydroxytetraperoxides.     

Stable Boron Peroxides with a Subporphyrinato Ligand

Subporphyrin B‐peroxides have been synthesized in good yields by acid‐catalyzed exchange reactions of subporphyrin B‐methoxide with the corresponding hydroperoxides. Thermal dimerization of the subporphyrin B‐hydroperoxide provided the peroxo‐bridged bis(subporphyrin) quantitatively. These subporphyrin B‐peroxides are fairly stable under ambient conditions, which allowed their isolation and full characterization as the first examples of structurally authenticated boron hydroperoxides, acyclic boron organylperoxides, and neutral peroxo‐bridged diboron species. The subporphyrin B‐peroxides thus prepared were investigated through their crystal structures, IR spectra, and cyclic voltammograms as well as by DFT calculations. The subporphyrin B‐hydroperoxide oxidizes triphenylphosphine quantitatively to triphenylphosphine oxide.     

1,2-二氧六环类抗疟过氧化物的合成

Synthesis of five simple analogues of peroxyplakoric acid by using Kobayashi＇s method to construct the key 1,2-dioxane core is detailed.     

Factors Affecting the Stability of Cellulose Peroxides

Factors affecting the stability of three kinds of cellulose peroxides prepared by reactions of aldehyde cellulose, carboxy-methyl cellulose, and unmodified cellulose with hydrogen peroxide, Peroxides A, B, and C, respectively, were investigated. The relative stability of the peroxides was in the order Peroxide A > B > C, which was greatly improved by applying ethylenediaminetetraacetic acid as the chelating reagent for the metals in a very small amount in the sample. The sample kept under nitrogen retained stable activity of the peroxide longer than that under air atmosphere. Water in the sample seemed to participate in the decomposition of the peroxide to some extent. The functions of metals, water, and atmosphere on the decomposition of peroxide are discussed.     

Gas Phase Structures of Peroxides: Experiments and Computational Problems

Gas‐phase structures of several organic and inorganic peroxides X‐O‐O‐X and X‐O‐O‐X′, which have been determined experimentally by gas electron diffraction and/or microwave spectroscopy, are discussed. The O?O bond length in these peroxides varies from 1.481(8) Å in Me₃SiOOSiMe₃ to 1.214(2) Å in FOOF and the dihedral angle ?(XO‐OX) between 0° in HC(O)O‐OH and near 180° in Bu^tO‐OBu^t. Some of the peroxides cause problems for quantum chemistry, since several computational methods fail to reproduce the experimental structures. Extreme examples are MeO‐OMe and FO‐OF. In the case of MeO‐OMe only about half of the more than 100 computational methods reported in the literature reproduce the experimentally determined double‐minimum shape of the torsional potential around the O?O bond correctly. For FO‐OF only a small number of close to 200 computational methods reproduce the O?O and O?F bond lengths better than ±0.02 Å.