Ketones table

Since muscone (101), by itself, does not reproduce the total odor impression of this musk, IFF chemists (56) as early as 1971 in an analysis of tincture of Tonquin musk, reported a series of macrocycHc ketones (Table 16) which play a key role in creating the characteristic odor of this musk (11). The introduction of a double bond into a macrocycHc ketone (eg, 102) changes the odor from flowery musk to animal musk. 

Reactions of fluoroxytrifluoromethane with enol ethers, enol acetates, and enamines [/, 2, 3] are very useful, especially for the preparation of steroidal ct-fluoTo ketones (Table 2, entries 1, 3, 5, 6, and 7) [7] (equation 12)... 

The DKRs of a-, (3-, y- and 8-hydroxy esters were also accomplished with PCL and 1 at 60-70°C. In the DKRs, the enantioselectivities were good in most cases though the yields were moderate. The use of H2 was necessary in the DKR of 7- and 8-hydroxy esters to suppress the formation of ketones (Tables 8-10). 

One of the potentially most useful aspects of the imine anions is that they can be prepared from enantiomerically pure amines. When imines derived from chiral amines are alkylated, the new carbon-carbon bond is formed with a bias for one of the two possible stereochemical configurations. Hydrolysis of the imine then leads to enantiomerically enriched ketone. Table 1.4 lists some examples that have been reported.118... 

The method (i) can be applied to the synthesis of almost all heavy ketones (Tables 3-5). Silanethiones and a silaneselone stabilized by the coordination of a nitrogen group have been synthesized by the method (ii) (Table 4). The method (iii) is effective to the synthesis of kinetically stabilized tricoordinate heavy ketones, although it cannot be applied to the synthesis of double-bond compounds between heavier group 14 elements and tellurium due to the instability of polytellurides (Table 3). The method (iv) can be used only when the unique dilithiometallanes can be generated (Table 3). The synthesis of heavy ketones by the method (v) demands the isolation of the corresponding heavy acyl chlorides as stable compounds (Table 5). 

Other functional groups which have a heteroatom rather than a hydroxyl group capable of directing the hydrogenation include alkoxyl, alkoxycarbonyl, carboxylate, amide, carbamate, and sulfoxide. The alkoxy unit efficiently coordinates to cationic iridium or rhodium complexes, and high diastereoselectivity is induced in the reactions of cyclic substrates (Table 21.3, entries 11-13) [25, 28]. An acetal affords much lower selectivity than the corresponding unsaturated ketone (Table 21.3, entries 14 and 15) [25]. 

Ferrocene-based complexes have some potential for the enantioselective reduction of ketones, but compared to other ligand classes this is relatively limited [3]. Rh complexes of bppfa, bophoz and josiphos are among the most selective catalysts for the hydrogenation of a-functionalized ketones (Table 25.9 Fig. 25.18, 30-32). Ru complexes of walphos and ferrotane are quite effective for... 

The asymmetric epoxidation reaction with polyleucine as catalyst may be applied to a wide range of a, 3-unsaturated ketones. Table 4.1 shows different chalcone derivatives that can be epoxidized with poly-L-leucine. The substrate range included dienes and tctracncs151. Some other examples were reported in a previous edition161 and by M. Lastcrra-Sanchcz171. 

The procedure is very easy to reproduce and the asymmetric transfer hydrogenation may be applied to a wide range of aromatic ketones. Table 9.3 gives different substrates that can be reduced with the Ru(II)-(2-azanorbornylmetha-nol) complex in Ao-propanol... 

Vinyl trifluoromethanesulfonates (triflates) are a new class of compounds, unknown before 1969, that have been used most extensively in solvolytic studies to generate vinyl cations.2,3,812 Three methods have been used to prepare these sulfonic esters. The first, involving the preparation and decomposition of acyltriazines,4 requires several steps to prepare the acyltriazines and is limited to the preparation of fully substituted vinyl triflates. The second method involves the electrophilic addition of trifluoromethanesulfonic acid to acetylenes5,8,15 and, consequently, is not applicable to the preparation of trisubstituted vinyl triflates and certain cyclic vinyl triflates. However, this second procedure is relatively simple and often gives purer products in higher yield than the subsequently discussed reaction with ketones. Table I lists vinyl triflates that have been prepared by this procedure. ... 

Although both boronates and alanates react with allylic bromides, aldehydes and C02 to afford allenic products in satisfactory yield, the alanates are more efficient in additions to ketones (Table 9.14). Boronate reagents do not require a B-C alkyl migration for their preparation. Thus the starting acetylene possesses the structural elements of the product. Additionally, the issue of dummy ligands is irrelevant. 

Catalysed oxidation of non-activated haloalkanes by hypochlorite provides an attractive low-cost and convenient procedure for their conversion into carbonyl compounds [6] primary haloalkanes produce carboxylic acids and secondary haloalkanes are converted into ketones (Table 10.12). Secondary amines are oxidized to ketones under analogous conditions, whereas primary amines yield nitriles (Table 10.13) [1,2], o-Nitroanilines are oxidized to benzofurazan-1-oxides [15]. 

Benzoisothiazole-2,2-dioxides undergo autoxidation under basic conditions in the presence of TBA-Br to yield 2-aroylaniline derivatives (Scheme 10.6) and the more simple diarylmethylsulphones produce diaryl ketones (Table 10.29) [1],... 

Oxidative cleavage of secondary acetonitriles to ketones (Table 10.30)... 

Brinkmeyer and Kapoor (101) reported that the chiral hydride complex formed from LAH and (+ )-90 (Darvon alcohol) gave high enantiomeric ratios of chiral propargylic carbinols in the reduction of acetylenic ketones (Table 10, entries... 

Toluene was chosen as the solvent in order to eliminate coordination involving solvent. Inconsistent variations were observed however, the most selective reagent was prepared with 107c in a 3 1 molar ratio of 107c LAH (Table 13), and this reagent was used to reduce several other aryl alkyl ketones (Table 13). 

Unfortunately, there are some limitations in the carboxylic acid group of compounds, and the derivatives most often used to form enolate anions are esters. However, esters are less acidic than the corresponding aldehydes or ketones (Table 10.2). 

In concurrent and independent work, Suzuki and Enders found that tethered keto-aldehydes undergo highly enantioselective cross-benzoin reactions using tria-zolium based catalysts [50, 51], The scope includes various aromatic aldehydes with alkyl and aryl ketones (Table 4). Additionally, aliphatic substrate 39a is cyclized in excellent enantioselectivity, albeit in 44% yield. 

In a report by Enders and co-workers, triazoUum pre-catalysts 42-44 were shown to be competent in the cyclization of a variety of ketones (Table 5) [50], Tetracyclic triazoUum pre-catalyst 44 provides the enantioselectivities up to 98%. 

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