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Alcohol cleavage

Cleavage TFA Product after cleavage Alcohol Aromatic compound... [Pg.215]

C—O bond cleavage. Alcohols are recovered after treatment of allyl ethers... [Pg.400]

The hydrogenolyaia of cyclopropane rings (C—C bond cleavage) has been described on p, 105. In syntheses of complex molecules reductive cleavage of alcohols, epoxides, and enol ethers of 5-keto esters are the most important examples, and some selectivity rules will be given. Primary alcohols are converted into tosylates much faster than secondary alcohols. The tosylate group is substituted by hydrogen upon treatment with LiAlH (W. Zorbach, 1961). Epoxides are also easily opened by LiAlH. The hydride ion attacks the less hindered carbon atom of the epoxide (H.B. Henhest, 1956). The reduction of sterically hindered enol ethers of 9-keto esters with lithium in ammonia leads to the a,/S-unsaturated ester and subsequently to the saturated ester in reasonable yields (R.M. Coates, 1970). Tributyltin hydride reduces halides to hydrocarbons stereoselectively in a free-radical chain reaction (L.W. Menapace, 1964) and reacts only slowly with C 0 and C—C double bonds (W.T. Brady, 1970 H.G. Kuivila, 1968). [Pg.114]

Primary alcohols do not dehydrate as readily as secondary or tertiary alcohols and their dehydration does not involve a primary carbocation A proton is lost from the (3 carbon m the same step m which carbon-oxygen bond cleavage occurs The mechanism is E2... [Pg.222]

In the presence of strong oxidizing agents at elevated temperatures oxidation of tertiary alcohols leads to cleavage of the various carbon-carbon bonds at the hydroxyl bearing carbon atom and a complex mixture of products results... [Pg.642]

The most intense peaks in the mass spectrum of an alcohol correspond to the ton formed according to carbon-carbon cleavage of the type shown ... [Pg.657]

The cleavage of ethers is normally earned out under conditions (excess hydrogen halide heat) that convert the alcohol formed as one of the original products to an alkyl halide Thus the reaction typically leads to two alkyl halide molecules... [Pg.674]

The saponification of 0 labeled ethyl propanoate was desenbed in Section 20 11 as one of the significant expenments that demonstrated acyl-oxygen cleavage in ester hydrolysis The 0 labeled ethyl propanoate used in this expenment was prepared from 0 labeled ethyl alcohol which in turn was obtained from acetaldehyde and 0 enriched water Wnte a senes of equations... [Pg.880]

Tetrahydrofurfuryl alcohol is surprisingly resistant to hydrogenolysis under vigorous conditions, however, cleavage of the ring or side chain occurs (126,127). [Pg.82]

Resorcinol or hydroquinone production from m- or -diisopropylben2ene [100-18-5] is realized in two steps, air oxidation and cleavage, as shown above. Air oxidation to obtain the dihydroperoxide (DHP) coproduces the corresponding hydroxyhydroperoxide (HHP) and dicarbinol (DC). This formation of alcohols is inherent to the autooxidation process itself and the amounts increase as DIPB conversion increases. Generally, this oxidation is carried out at 90—100°C in aqueous sodium hydroxide with eventually, in addition, organic bases (pyridine, imidazole, citrate, or oxalate) (8) as well as cobalt or copper salts (9). [Pg.488]

Substitution Reactions on Side Chains. Because the benzyl carbon is the most reactive site on the propanoid side chain, many substitution reactions occur at this position. Typically, substitution reactions occur by attack of a nucleophilic reagent on a benzyl carbon present in the form of a carbonium ion or a methine group in a quinonemethide stmeture. In a reversal of the ether cleavage reactions described, benzyl alcohols and ethers may be transformed to alkyl or aryl ethers by acid-catalyzed etherifications or transetherifications with alcohol or phenol. The conversion of a benzyl alcohol or ether to a sulfonic acid group is among the most important side chain modification reactions because it is essential to the solubilization of lignin in the sulfite pulping process (17). [Pg.139]


See other pages where Alcohol cleavage is mentioned: [Pg.1285]    [Pg.185]    [Pg.463]    [Pg.1285]    [Pg.185]    [Pg.463]    [Pg.344]    [Pg.284]    [Pg.65]    [Pg.47]    [Pg.111]    [Pg.159]    [Pg.165]    [Pg.278]    [Pg.282]    [Pg.5]    [Pg.325]    [Pg.254]    [Pg.728]    [Pg.24]    [Pg.212]    [Pg.344]    [Pg.139]    [Pg.103]   
See also in sourсe #XX -- [ Pg.77 , Pg.184 ]




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