Ketone infrared absorption

Carvone (Problem 12.39) has an intense infrared absorption at 1690 cm-1. What kind of ketone does carvone contain ... 

Table 19.2 I Infrared Absorptions of Some Aldehydes and Ketones...

Catalytic dehydrogenation of alcohol is an important process for the production of aldehyde and ketone (1). The majority of these dehydrogenation processes occur at the hquid-metal interface. The liquid phase catalytic reaction presents a challenge for identifying reaction intermediates and reaction pathways due to the strong overlapping infrared absorption of the solvent molecules. The objective of this study is to explore the feasibility of photocatalytic alcohol dehydrogenation. 

In some cases it is possible to differentiate between the various alkyl substituents. Primary, secondary and tertiary nitrates and nitrites all show clearly different infrared absorptions. The spectra of acid fluorides can be used to differentiate chain-end groups from pendant acid groups. Furthermore, the loss of all -OH species upon sulfur tetrafluoride exposure allows the reliable estimation of ketones, esters and lactones without the complication of hydrogen-bonding induced shifts in the spectra. Preliminary results from the use of these reactions to characterize y-ray oxidized polyethylene and polypropylene are used to illustrate the scope of the methods. 

The pure, more highly substituted olefin, n2Sd 1.3840, could also be separated by preparative gas chromatography, and the unchanged ketone could be separated from the two triflate isomers by chromatography on a silica gel column with pentane as the eluant. The pure product has infrared absorption (CC14 solution) at 1700 (enol C=C), 1210 and 1140 cm.-1 (S02) with end absorption in the ultraviolet (heptane... 

U. Dabrowski, Yu. A. Pentin, J. Dabrowski, V. M. Tatevskii, and N. K. Kochetkov, Tauto-merism investigation of alkyl p-aminovinyl ketones from infrared absorption spectra, Zh. Fiz. Khim., 32 (1958) 135-140. 

The infrared absorption spectra of four octyl alcohols, using a cell length of 0.1 mm., are shown in Fig. 3 (a) 1-octanol, (b) 9.2 vol. % solution of 1-octanol-d in 1-octanol, (c) 1 octanol-2-d, (d) l-octanol-2-d exposed to ketone-synthesis conditions. 

Identification The infrared absorption spectrum of the sample exhibits relative maxima at the same wavelengths as those of a typical spectrum as shown in the section on Infrared Spectra, using the same test conditions as specified therein. Assay Not less than 50.0%, by volume, of ketones as carvone. 

Another unique compound was found7(g) among the products of the reaction between 3,5,6-tri-O-methyl-D-glucose and acetylmethylene-phosphorane. An inflection at 222 nm in the electronic spectrum, and strong infrared absorption at 5.8 /am, indicated an a,/3-unsaturated, cyclic ketone structure.89 When this compound was allowed to react with methylmagnesium bromide, the product showed7 8 an absence... 

Compound A is a cyclic, nonconjugated keto alkene whose carbonyl infrared absorption should occur at 1715 cm-. Compound B is an a,B-unsaturated, cyclic ketone additional conjugation with the phenyl ring should lower its IR absorption below 1685 cm-1. Because the actual IR absorption occurs at 1670 cm-1, B is the correct structure. 

The hydrogen-bonding group of each polymer has been taken as equivalent to that of the parent mononrer. (The hydrogen-bonding tendency can be assigned qualitatively in the order alcohols > ethers > ketones > aldehydes > esters > hydrocarbons or setniquantitatively from infrared absorption shifts of CH rOD in a reference solvent and in the liquid of interest (7J.)... 

The relative stabilities of olefinic bonds at various positions in the steroid nucleus have a direct bearing on reactions of several kinds, including elimination reactions Chapter 3), enolisation of ketones (Chapter 4) and the equilibration of olefinic structures (Chapter 5). Infrared absorption spectra in the region 1600-1700 cm""i, which for cyclohexene (1650 cm" ) and cyclopentene (1613 cm " ) reflect the greater strain (5-6 kcal/mole) present in cyclopentene [43], have been employed [44,45] to obtain some indication of the relative stabilities of cis-disubstituted and trisubstituted double bonds. The data are summarised in Table 2. 

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