Cyclic, from cycloalkyl

Rearrangement alkylation of cycloalkylhydroxylamine carbonates." These hy-droxylamines, which can be prepared from cycloalkyl amines or cyclic ketones, on reaction with a trialkylaluminum rearrange to an a-alkyiated nitrogen-containing heterocycic. The complete sequence is formulated for synthesis of an a-alkylatcd piperidine (equation I). 

The present preparation illustrates a general and convenient irethod for ring contraction of cyclic ketones. The first step is the usual procedure for the preparation of enamines. The second step involves 1,3-dipolar cycloaddition of diphenyl phosphorazidate to an enamine followed by ring contraction with evolution of nitrogen. Ethyl acetate and tetrahydrofuran can be used as a solvent in place of toluene. Pyrrolidine enamines from various cyclic ketones smoothly undergo the reaction under similar reaction conditions. Diphenyl (cycloalkyl-1-pyrrolidinylmethylene)phosphoramidates with 5,6,7, and 15 members in the ring have been prepared in yields of 68-76%. 

SiO)2Ta Cp[ activates, at room temperature, the C-H bonds of cyclic alkanes (from cyclopentane to cyclooctane) to form the corresponding surface tantalum-cycloalkyl stoichiometrically with evolution of hydrogen (Scheme 3.2) [20] ... 

Achiral cycloalkyl quaternary amino acids have also been incorporated into model peptides using 5(47/)-oxazoIones as intermediates. A comparative study between cyclic and acyclic derivatives has been described. The influence of the ring size of a homologous series from l-aminocyclopropanecarboxylic acid to... 

Alkyl/cycloalkyl alkylphosphonofluoridates are generally obtained from an organophosphorus precursor, typically an alkylphosphonic difluoride, and an alcohol. In 1992, over 300 aliphatic and cyclic alcohols were found to be commercially available as fine chemicals, of which inexpensive primary and secondary alcohols are considered suitable for chemical weapons production. By these criteria, approximately 70 alcohols remain of prime interest for the preparation of Schedule l.A.l chemicals. Only pinacolyl alcohol, the precursor of soman, is contained in the CWC Schedule... 

Esters have been prepared in 63-73% yields from several simple cycloalkyl and aryl alkyl ketones by reaction at room temperature with per-benzoic acid. The larger radical of the ketone appears as the alcohol fragment of the ester. Cyclic ketones are oxidized by potassium persulfate and sulfuric acid to esters from which o>-hydroxy aliphatic esters are obtained upon hydrolysis and reesterification. Peracetic acid in acetic anhydride converts salicylaldehyde to o-hydroxyphenyl formate (88%). ... 

In addition to the presented Sjj/Michael transformations, a twofold domino Sn/Sn cycloalkylation of stabilized carbanions from cyclic P-ketoesters with 1,4-dibromobut-2-yne yielding annulated 2-vinyHdenehydrofurans has been reported... 

The second catalyst component was a solution of an aluminoxane in a hydrocarbon solvent, selected from between aluminoxanes (i) linear, R AIO (R A10) -A1R 2 [where R is C1.20 alkyl and cycloalkyl and m = 0 or an integer], and (ii) cyclic,... 

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