Cycloalkanes nitro

Polynitro-aromaten werden in erster Stufe mit schwachen Hydrid-Donatoren zu den Meisenhcimer-Komplexen7 hydriert (s. S. 90), die dann durch Natriumboranat zu Polyni-tro-cycloalkanen8 weiterreduziert werden konnen (s. S. 88ff.) (s.a. Bd. X/l, S. 128). Mit Natriumboranat werden direkt die entsprechenden aci- Ni tro-cycloalkene oder -cycloalkane erhalten8 (Die Nitro-Gruppe wird kaum angegriffen). 

Nitromethyl-l-oxo-cycloalkane bzw. 1-Nitromethyl-cycloalkene lassen sich mit Pyrro-lidinen oder (S,)-2-Methoxymethyl-pyrrolidin bzw. -piperidin in Acetonitril bei 20° unter Austausch der Nitro-Gruppe in guten Ausbeuten in 2-(Pyrrolidino-methyl)-l-oxo-cycloalkane3 bzw. l-(Piperidino-methyl)-cycloalkene8 uberfuhren (s.a. S. 378) ... 

Nitro-alkane bzw. -cycloalkane reagieren bei der Behandlung mit Stickstoffbasen, z. B. l.S-Diaza-bicyclo. S.OJnon-S-en1, l,7-Diaza-bicyclo[5.4.0]undec-7-en1 3 oder Diisopro-pylamin4,5 sowie durch Erhitzen in aromatischen Losungsmitteln6 unter Eliminierung von Salpetrigsaure zu Olefinen. 

Various ttan,v-l-nitro-2-(phenylseleno)cycloalkanes 60 have been prepared in moderate yield by treatment of the cycloalkene with phenylselenenyl bromide followed by addition of silver nitrite in dichloromethane/acetonitrile67, 2-Phenylseleno-l-cycloalkanols are also formed in substantial amounts when moisture is not rigorously excluded67. 

The first step was the bromination of the oxime with bromocuccinimide to yield a bromonitroso compound on which the oxidation of hydrogen peroxide with nitric acid was transformed into bromonitro compound. The latter by acting with sodium borohydride furnished a secondary nitro compound with a yield of 33-80%. The method was particularly suitable for the formation of nitro derivatives of nitro cycloalkanes. The method is unsuitable for aromatic ketoximes and aldoximes. However, Barnes and Patterson [73] extended the method to aldoximes by using ozone as an oxidizing agent on gem-chloro ... 

Gasoline hydrocarbons volatilized to the atmosphere quickly undergo photochemical oxidation. The hydrocarbons are oxidized by reaction with molecular oxygen (which attacks the ring structure of aromatics), ozone (which reacts rapidly with alkenes but slowly with aromatics), and hydroxyl and nitrate radicals (which initiate side-chain oxidation reactions) (Stephens 1973). Alkanes, isoalkanes, and cycloalkanes have half-lives on the order of 1-10 days, whereas alkenes, cycloalkenes, and substituted benzenes have half- lives of less than 1 day (EPA 1979a). Photochemical oxidation products include aldehydes, hydroxy compounds, nitro compounds, and peroxyacyl nitrates (Cupitt 1980 EPA 1979a Stephens 1973). 

More complex products are obtained from cyclizations in which the oxidizable functionality and the alkene are present in the same molecule. y9-Keto esters have been used extensively for Mn(III)-based oxidative cyclizations and react with Mn(OAc)3 at room temperature or slightly above [4, 10, 11, 15], They may be cyclic or acyclic and may be a-unsubstituted or may contain an a-alkyl or chloro substituent. Cycloalkanones are formed if the unsaturated chain is attached to the ketone. y-Lactones are formed from allylic acetoacetates [10, 11]. Less acidic /3-keto amides have recently been used for the formation of lactams or cycloalkanones [37]. Malonic esters have also been widely used and form radicals at 60-80 °C. Cycloalkanes are formed if an unsaturated chain is attached to the a-position. y-Lactones are formed from allylic malonates [10, 11]. yff-Diketones have been used with some success for cyclizations to both alkenes and aromatic rings [10, 11]. Other acidic carbonyl compounds such as fi-keto acids, /3-keto sulfoxides, j8-keto sulfones, and P-nitro ketones have seen limited use [10, 11]. We have recently found that oxidative cyclizations of unsaturated ketones can be carried out in high yield in acetic acid at 80 °C if the ketone selectively enolizes to one side and the product cannot enolize... 

Auch Amino-, Nitro- oder anorganische Ester-Gruppen erleichtern den oxidativen Angriff auf Alkane, Cycloalkane oder aromatische Seitenketten. Beispielsweise werden amino-substituierte Cyclohexane mit Salpetersaure unter relativ milden Bedingungen in guter Ausbeute zu Dicarbonsauren gespalten (vgl. Bd. IV/la, S. 714, 720). 

A new route to lactams (e.g. e-caprolactam, 96%) by the reaction of 1-nitroso-and 1-nitro-l-halogeno-cycloalkanes, e.g. (12), with triphenylphosphine, or via the one-step reaction of the cycloalkanone oxime with halogen and triphenylphosphine, goes via successive Perkov and Beckmann reactions, " as shown in Scheme 1. 

An improved one-step conversion of alicyclic ketones (30) into lactams (31 n = 3-10) involves the use of hydroxylamine-O-sulphonic acid and methanoic acid at reflux temperature. Treatment of 1-chloro-l-nitroso- and 1-chloro-l-nitro-cycloalkanes (32) with PhaP and then hydrolysis of the intermediate chloro-imine provides a new route to (31 n — 3-6, or 10)." ... 

From To - Alkanes Cycloalkanes Alkenes Alkynes Aryls Halogen compounds Alcohols Phenols Ethers, Quinones B. and Si compounds P and 6i compounds Nitro, Nitroso, Azo, Azoxy, Hydrazo, ides Amines Organometallic Aldehydes Ketones Acids, Anhydrides, Esters Arn.des, Amidines, Nitriles Hydroky-aldehydes Amino Heterocycles Nucleosides Miscellaneous, including heterocycles... 

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