Alcohols cycloalkyl

Dimethyl sulfoxide reacts with trifluoroacetic anhydride at low tempera ture to give a complex that is an efficient reagent for the oxidation of alcohols to carbonyl compounds [40 41] This reagent can be used to oxidize primary and secondary aliphatic alcohols, cycloalkyl alcohols, and allylic, homoallylic, ben-zylic, acetylenic, and steroidal alcohols (equation 19)... 

A mixture of water/pyridine appears to be the solvent of choice to aid carbenium ion formation [246]. In the Hofer-Moest reaction the formation of alcohols is optimized by adding alkali bicarbonates, sulfates [39] or perchlorates. In methanol solution the presence of a small amount of sodium perchlorate shifts the decarboxylation totally to the carbenium ion pathway [31]. The structure of the carboxylate can also support non-Kolbe electrolysis. By comparing the products of the electrolysis of different carboxylates with the ionization potentials of the corresponding radicals one can draw the conclusion that alkyl radicals with gas phase ionization potentials smaller than 8 e V should be oxidized to carbenium ions [8 c] in the course of Kolbe electrolysis. This gives some indication in which cases preferential carbenium ion formation or radical dimerization is to be expected. Thus a-alkyl, cycloalkyl [, ... 

Reaction of styrene oxide with tetraallyltin in the presence of Bi(OTf)3 (2 mol%) affords the corresponding l-phenyl-4-penten-2-ol (Fig. 5). In a similar fashion, various aryl substituted epoxides react smoothly with tetraallyltin to give the corresponding homoallylic alcohols. This method give generality as cycloalkyl oxiranes and sterically hindered ones give the corresponding homoallylic alcohols. 

Likewise Bi(OTf)3 catalyzes the reaction of aziridines to give the corresponding (3-amino alcohols (Fig. 8). In the case of cycloalkyl aziridines, the stereochemistry of the ring-opened products was found to be trans. This method has some additional features of green aspects as it allows the recovery and re-usability of the catalyst. 

Heterobimetallic homogeneous catalysts [e.g. (12)] have been developed26 for the alkylation of a range of aromatic compounds by n-activated alcohols. The superior electrophilicity is attributed to the high-valent T-Sn core in the structures. A review has appeared of reactions involving the hydroxyalkylation and cycloalkylation of arenes by hydrofurans, lactones, and unsaturated acids 27... 

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... 

Durst et al. (29) made microscale synthesis of several sarin analogues in autosampler vials and analyzed them directly with a gas chromato-graphy/infrared spectroscope/mass spectrometer (GC/IR/MS) instrument. Ninety different alkyl and cycloalkyl alcohols were used. They presented a couple of light-pipe IR spectra and a table of typical gas-phase frequencies (vp F, vp=0, pP methyl, 8S P methyi, vp 0 c) for 12 sarin-type chemicals. 

The direct functionalization of arenes by primary alcohol sulfonate esters has also been reported.44 5mol% AUCI3/AgOTf was again used as catalyst and high yields (up to 92%) of products obtained in some cases. Higher yields (e.g. 97, 93%) were obtained in intramolecular cycloalkylation reactions of a similar type. 

As in the selenium case (Scheme 17) the oxidation of alkyl phenyl telluride with excess MCPBA in the presence of alcohols results in a facile substitution of a PhTe moiety by an alkoxy group. The reaction is assumed to proceed via a similar tellurone-MCPBA adduct intermediate. Oxidation of cycloalkyl telluride (61) was accompanied by ring contraction to produce an acetal (62), < while the bromination-hydrolysis method affords the allylic ether by telluroxide elimination (Scheme 22). ... 

In a similar way, the reaction of xanthates under radical conditions leads to products and selectivities that are totally different from those in thermal rearrangements. The radical transformation usually furnishes unsubstituted hydrocarbons as reaction products. The major accomplishment of the reaction is the deoxygenation of secondary alcohols to furnish the corresponding hydrocarbons when tributylstannane is used with 0-cycloalkyl thiobenzoates or S-methyl dithiocarbamates [13]. However, the rearranged product may be observed as a byproduct [14,15]. 

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%). ... 

Multiple intramolecular ring closures of aryl-substituted unsaturated long chain alcohols, acids, acid chlorides and ethers in the presence of Friedel-Crafts catalysts have been extensively employed to synthesize polynuclear hydroaromatic hydrocarbons and polycyclic ketones. This is illustrated by two examples shown in equations (112) and (113). The application of stereospecific cycloalkylations in approaching the synthesis of complex organic molecules has been reviewed by Barclay. ... 

Olefins and allylic alcohols from alkyl or cycloalkyl bromides and from epoxides (general procedures The i-alkyl or cycloalkyl bromide is treated with sodium phenyl tellurolate (1 equiv from diphenyl ditelluride and NaBH, see Section 3.1.3.2). The crude telluride is purified by SiOj chromatography (elution with hexane) and converted into the corresponding dibromide by addition of bromine (1 equiv) in CCI4, at 0°C. Epoxides are converted into j8-hydroxylalkyl and )3-hydroxycycloalkyl phenyl tellurium dibromide by a similar procedure, except that the intermediate tellurides are chromatographed on SiOj using hexane/EtOAc (5 1) as the eluent. 

Scheme 2.53 Examples of the fluorination of alcohols with a,a-clifluoroalkylamines or a-fluroro-enamines. Synthesis of cycloalkyl fluorides, fluorosteroids, fluoroterpenes, and glycosyl fluorides with G-fluoroenamines [122, 123].

In the case of nucleophilic radicals, mainly alkyl and cycloalkyl radicals, an Sh2 reaction occurs at the 0—0 peracid bond and results in an alcohol. If the... 

The reduction of ketones into alcohols can be achieved using biocatalytic methods. Amongst the most popular of the available methods is the use of Baker s yeast, BY (Saccharomyces cerevisiae). The use of P-ketoesters as substrates leads to the corresponding p-hydroxy esters, often with high enantioselectivity. In the particular case of a-substituted P-ketoesters, the substrates spontaneously racemize, and this provides the basis for many reports of dynamic resolution reactions, some of which are described in the following discussion. In 1976, Deol and co-workers showed that cycloalkyl p-ketoesters could be reduced under dynamic resolution conditions (Fig. 9-26) >58l... 

The benzyl ethers (223) photochemically cleave to form alcohols ROH (R = alkyl, cycloalkyl, or 2-pyrrolidinoethyl) in acetonitrile/water. The reaction involves sinsls electron... 

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