Acyl nitrates unsaturated

The photochemical cyclisation of p.y-unsaturated ketoximes to 2-isoxazolines, e.g., 16—>17, has been reported <95RTC514>. 2-Isoxazolines are obtained from alkenes and primary nitroalkanes in the presence of ammonium cerium nitrate and formic acid <95MI399>. Treatment of certain 1,3-diketones with a nitrating mixture generates acyl nitrile oxides, which can be trapped in situ as dipolar cycloadducts (see Scheme 3) <96SC3401>. 

It was found that the 15-membered macrocyclic complexes were significantly less acidic. Similar reversible protonations have been shown to occur in related macrocyclic complexes36 37 and this work has been developed by Busch into a major study of ligand reactions,38 which are summarized in equations (16)—(19). It is significant that these reactions include not only typical substitution reactions such as acylation and nitration (equations 16 and 19), but also nucleophilic addition to isocyanates (equation 17) and to a, 3-unsaturated esters (equation 18). 

Glycol mononitrate has aroused a certain amount of interest. Twist and Baughan (109) examined the vapour pressure of the solution of this substance, and of a number of other nitrate esters, and found the deviations from Raoult laws to be of the same order as those observed by Chedin and Vandoni for nitrocellulose [110]. Prior to this work Marans and Zelinski (III] prepared a number of mixed esters of the type XI where R are unsaturated acyls apt to polymerize and thus to give combustible polymers. 

Esters from unsaturated fatty acid chlorides are usually viscous or limpid oils soluble in hydrocarbons and turpentine, and whose primary applications are as varnishes, films, artificial threads, aqueous emulsions, and rubber-like plastics.2067,2068 Heating them in an inert gas produced insoluble products formed by polymerization involving double bonds in the acyl moieites.2069 As mentioned in the section on nitrates, acetates of amylose are less compact than amylopectin acetate.1468 Esters of unsaturated acids have also been proposed as re-moistenable adhesives.1971 1972... 

Reaction with Allylic and Benzylic Electrophiles. The acyl radicals can be trapped with halogen- and silicon-based electrophiles. a -Allylation of a, -unsaturated ketones is done while using Mn(OAc)3 dihydrate and allyl bromide in refluxing benzene (eq 29). Better yields are usually observed for cyclopen-tenones compared to cyclohexenones. a -Benzylation is also possible using benzyl bromide as the electrophilic partner (eq 30). Both methods tolerate a range of substitution, including 8-alkoxy-a, -unsaturated ketones. It is possible to perform a sequential allylation/cyclization with an excess of allyltrimethylsilane (eq 31). Mn(OAc)3 offers good conversions, but the use of ceric ammonium nitrate (CAN) as co-oxidant improves yields. 

Suspension polymerization was applied to prepare polynor-bomene aosslinked beads suitable for use as supports in organic synthesis. The monomers used included norbor-nene, norbom-2-ene-5-methanol, and aosslinking agents including bis(norbom-2-ene-5-methoxy)alkanes, di(norbom-2-ene-5-methyl)ether, and l,3-di(norbom-2-ene-5-methoxy) benzene. The initial resins, which were unsaturated, were subsequently modified using hydrogenation, hydrofluorination, chlorination, or bromination to yield saturated resins with varying properties. They were reported to be superior to more traditional styrene-divinylbenzene resins due to reduced interference in electrophilic aromatic substitution reactions (e.g., Friedel-Crafts acylation and nitration). 

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