Ketones group

Both maltose and lactose, being reducing sugars, give osazones which differ from one another and from glucosazone in crystalline form. Sucrose (G-r-r-F), having no potential aldehyde or ketone grouping, does not form an osazone. 

The secondary alcohol group, -CH(OH) in benzoin is readily oxidised to a ketone group, and thus benzil, a diketone, is obtained. 

The trisannulation reagent 7-acetoxy-l,l l-dodecadien-3-one (134) is derived from the bisannulation reagent 124 in four steps. This reagent is a synthetic equivalent of l-dodecene-3,7,11-trione, and the two ketone groups of the trione are masked as an acetoxy and a terminal alkene. The synthesis of optically active D-homo-19-norandrosta-4-en-3-one (135) by the trisannulation reaction... 

A more effective approach to enhancing the rate of photodegradation of PS is to copolymerize styrene with a small amount of a ketone-containing monomer. Thus the ketone groups are attached to the polymer during its manufacture (Pig. 13) (98,100). 

Pig. 13. Incorporation of photosensitive ketone groups into PS during manufacture by copolymerization of styrene and vinyl ketone. 

Attaching the ketone groups to the polymer backbone is more efficient on a chain scission/ketone basis because some of the light energy that the pendent ketone absorbs leads direcdy to chain scission via the Norrish type II mechanism, as well as photooxidation via the Norrish type I mechanism (see... 

The basic carbohydrate molecule possesses an aldehyde or ketone group and a hydroxyl group on every carbon atom except the one involved in the carbonyl group. As a result, carbohydrates are defined as aldehyde or ketone derivatives of polyhydroxy alcohols and their reaction products. A look at the formula for glucose shows that it contains hydrogen and oxygen atoms in the ratio in which they are found in water. The name carbohydrate... 

Oxidation of hydioxyl groups to carbonyl groups can form molecules with two aldehyde groups (dialdoses), two ketone groups (diuloses), or an aldehyde and a ketone group (osuloses). Keto acids are known as ulosonic acids. 

Fig. 1. Carotenoid pigments -carotene (42), P-apo-8 -carotenal (44), and canthaxanthin (43) = structure (42) with ketone groups at the 4 and 4 positions.

CH CO n CH,CO (ketone group as any group except second carbon) ... 

Photodegradation may involve use of inherently photo-unstable polymers or the use of photodegradant additives. An example of the former are ethylene-carbon monoxide polymers in which absorption of light by the ketone group leads to chain scission. The polymer becomes brittle and forms a powder. Such materials are marketed by Dow and by Du Pont. Other examples are the copolymers of divinyl ketone with ethylene, propylene or styrene marketed by Eco Atlantic. 

Although the nature of the general polar effect suggested by Kamernitzsky and Akhrem " to account for axial attack in unhindered ketones is not clear, several groups have reported electrostatic interactions affect the course of borohydride reductions. Thus the keto acid (5a) is not reduced by boro-hydride but its ester (5b) is reduced rapidly further, the reduction of the ester (6b) takes place much more rapidly than that of the acid (6a). Spectroscopic data eliminate the possibility that in (5a) there is an interaction between the acid and ketone groups (e.g. formation of a lactol). The results have been attributed to a direct repulsion by the carboxylate ion as the borohydride ion approaches. " By contrast, House and co-workers observed no electrostatic effect on the stereochemistry of reduction of the keto acid (7). However, in this compound the acid group may occupy conformations in which it does not shield the ketone. Henbest reported that substituting chlorine... 

The double bond of a, -unsaturated ketones reacts with nitrosyl fluoride but only at room temperature and in small yield. Cholestenone produces a 4.2% yield of a 4< -fluoro-5( -nitro-3-ketone (46) after alumina chromatography. Similarly, the A -20-ketone grouping in 3j5-acetoxypregna-5,16-dien-20-one (47) reacts to form after chromatography a 14% yield of the... 

A-ring conjugated ketones do not normally interfere with the epoxidation reaction, but hydride reduction will reduce any ketone groups to alcohols. These can be reoxidized by conventional means. 

It should be noted that the action of phenylhydrazine on the ketone group, and of diazobenzene salts on the methylene group situated between two CO groups, are analogous to that of hydrovylaniine and nitrous acid upon these two groups, of which the following are examples —... 

If a molecule contains both a ketonic and aldehydic carbonyl group, a secondary amine will react with the aldehydic carbonyl group to give a -enamino ketone (15). This has been shown not only for 2-formylcyclo-hexanone (14) (32,33) but also in steroidal systems when the aldehyde and ketone groups are in five- or six-membered rings (34). 

The composition of the products is reminiscent of the decomposition of the trialkyl-oxaziranes by ferrous salts. Here also the nitrogen atom is dealkylated and the carbon atom of the oxazirane ring is found as a ketone group. 

The reactions of diazomethane with heterocycles containing a ketonic grouping in the ring do not differ, in principle, from those of alicyclic ketones (see footnotes 3 and 177) ring expansion and the formation of epoxides compete. In general, ring expansion is the more important reaction for example, tetrahydropyran-4-one (99) is converted to l-oxacycloheptan-4-one (100) (60%) and 4,4 -epoxy-4-methyltetrahydropyran (101) (23%). ... 

By reduction carvone fixes 2 atoms of hydrogen on to the ketonic group, and 2 atoms in the nucleus, with the formation of dihydrocarveol, CijHjgO, whose corresponding ketone, dihydrocarvone, Cj Hj O, exists in small quantities in caraway oil. 

Translate oxy- by hydroxy- when it designates hydroxyl, as is commonly the case. When oxy- designates the ketonic group it is preferably translated OXO-. 

Among organic materials, poly(aryl ethers) and poly (aryl sulfides) have been known, as a class of engineering thermoplastics. The electron withdrawing sulfone and ketone groups usually activate the dihalo or dinitro compounds to facilitate the nucleophilic displacement through the transition state called Meisenheimer-Iike complex, and, thus, poly(aryl ether or sulfide) sulfones... 

From the data given in Table 5, it can be seen that ligands with ester and ketone groups (3 and 4) are more effective at extracting Na"" and ions than other ligands. This conclusion is not new, however, and has been... 

Ketones are named by replacing the terminal -e of the corresponding alkane name with -one. The parent chain is the longest one that contains the ketone group, and the numbering begins at the end nearer the carbonyl carbon. As with alkenes (Section 6.3) and alcohols (Section 17.1), the locant is placed before the parent name in older rules but before the suffix in newer IUPAC recommendations. For example ... 

Methyl 4-oxcpentanoate (an ester with a ketone group)... 

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