Oxygen cycloalkylation

Dialkyl peroxides have the stmctural formula R—OO—R/ where R and R are the same or different primary, secondary, or tertiary alkyl, cycloalkyl, and aralkyl hydrocarbon or hetero-substituted hydrocarbon radicals. Organomineral peroxides have the formulas R Q(OOR) and R QOOQR, where at least one of the peroxygens is bonded directly to the organo-substituted metal or metalloid, Q. Dialkyl peroxides include cyclic and bicycflc peroxides where the R and R groups are linked, eg, endoperoxides and derivatives of 1,2-dioxane. Also included are polymeric peroxides, which usually are called poly(alkylene peroxides) or alkylene—oxygen copolymers, and poly(organomineral peroxides) (44), where Q = As or Sb. 

Addition of an organolithium and Grignard reagent across the peroxy bridge of endoperoxides gives c/s-cyclohex-2-en-l,4-diols. Alkyl, cycloalkyl, alkenyl and aryl moieties can be transferred to oxygen <96TL6635>. 

Oxygen is one of the five (C, H, N, O, and S) major elements in resids and asphalt, although the level rarely exceeds 1.5% by weight. Many petroleum products do not specify a particular oxygen content, but if the oxygen compounds are present as acidic compounds such a phenols (Ar-OH) and naphthenic acids (cycloalkyl-COOH), they are controlled in different specifications by a variety of tests. 

Several perfluoroalkyl and cycloalkyl bromides were tested for potential as oxygen carriers, blood substitutes, radiopaque agents, for other medical applications or as intermediates. Their LD50 toxicity data are listed in Table 14 (for additional information, see also ref 2). 

C NMR spectroscopic and theoretical studies (DFT, ab initio, IGLO) of a series of cycloacylium ions were performed by Prakash et al.577 The study showed that the cycloalkyl groups have little effect on the shift of the carbocationic carbon. Furthermore, charge calculations showed that the delocalization into the cycloalkyl group is greater than in the protonated carboxylic acid (carboxonium ion), where two oxygen atoms participate in delocalization. 

Among the reactions applied in the synthesis of fullerene derivatives cycloaddition reactions such as [2 + 1]-, [2 + 2]-, [3 + 2] and [4 + 2] cycloadditions play a dominant role. In these reactions ring-fused fullerene derivatives are obtained, at least with incorporation of heteroatoms such as oxygen, nitrogen, or silicon. In this section photochemical reactions leading to cycloalkyl ring-fused fullerene adducts will be presented. Photocycloaddition reactions leading to C6o-fused heterocycles will be discussed later. 

X2 is hydrogen, 1-6 carbon alkyl, 1-6 carbon haloalkyl, 1-6 carbon cycloalkyl or phenyl which may be substituted by one or two halogen atoms, 1-3 carbon alkyl, 1-3 carbon alkoxy or nitro groups or X2 together with XI, is an oxygen atom or an alkylene having from 2-5 carbon atoms or... 

Self-terminating radical oxygenations are not restricted to cyclic alkynes. Electro-and photochemically generated NO3 can be used for the oxidative cyclization of cycloalkyl-clamped alkynes 67 (Scheme 2.12). This reaction leads to formation of anelated tetrahydrofurans (68 with X = or pyrrolidines (68 with X = NTs,... 

With dibromomethane compound 93 also undergoes cycloalkylation at both the oxygen and nitrogen atoms to form an oxazine (95).8 Other reactions utilizing the bifunctionality of compound 93 to produce cyclized derivatives such as 95 are discussed in greater detail in Section IV. 

The Parham cycloalkylation has been extended to provide a general route to oxygen heterocycles thus the reaction of (141) with butyl-lithium at — 100°C, followed by warming to 25°C, gives the 1-benzoxepin (142) in > 70% yield. ... 

A large number of perfluorinated heterocyclic compounds was prepared (mostly using ECF technology) in 1970-1990 during the quest for the best materials to be used as oxygen carriers in perfluorocarbon emulsions, so-called blood substitutes (for detailed review on this effort, see Ref. 34). The list of synthesized materials includes perfluorinated A-alkyl(cycloalkyl) pyrrolidines, oxazolidines, piperidines and... 

Exclusive cleavage of the cycloalkyl carbon-oxygen bond occurs on treatment of cycloalkyl methyl and ethyl ethers with acetyl chloride in the presence of a Lewis acid catalyst. 

As an alternative to the procedure used in Scheme 41 for excising the cycloalkyl moiety, the Baeyer-Villiger oxidation was applied to the dihydro derivative of (184). Gratifyingly, oxygen-insertion occurs predominantly at the bond of higher electron density to give the bis-acetal... 

Pure NO does not react directly with many organic compounds, but it becomes a strong nitrosating agent in the presence of molecular oxygen via reaction (Equation 3.18) and subsequent conversion into N Oj. For instance, the interaction of NO-O mixture with cycloalkyl alcohols in acetonitrile produces the corresponding nitrites [29] ... 

The magnitude of the dipole moment of phenol is also slightly less than that of cyclohexa-nol, its cycloalkyl counterpart, but in the opposite direction. The oxygen atom is the positive end of the dipole in phenol. 

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