Methyl phenyl ketone, substituted

When one carries out a VNS of 2-nitrothiophene with a-chloroacetophenone in the presence of t-BuOK, (2-nitrothien-3-yl)methyl phenyl ketone 80 is formed [159, 171], but the reaction with a-chloronitronate anion in the presence of KOH, instead of the expected nitroalkane, gave the ketone 81. The substitution in this case took place at C-5 [159, 168]. Nitroarylnitronate was formed as an intermediate in this reaction, and it was transformed into the final ketone probably by a Nef reaction during work-up (Scheme 113). 

A range of different functional groups has been introduced into the V-position of the C3 side chain, as shown in Table 6.10. A number of different functionalities were shown to be tolerated in this position, with lipophilic groups such as methyl and dithiolane being preferred over polar groups such as ketones and alcohols. Ketone (118) had similar CBi receptor affinity to the unfunctionalised -heptyl compound (84), while alcohol (120) had lower affinity. The phenyl ketone (119) had lower CBi receptor affinity than the simple benzyl-substituted compound (116), but higher CB2 affinity, with about 12-fold selectivity for CB2 over CBi. 

For the addition of ethylene, EtOAc as solvent was particularly advantageous and gave 418 in 60% yield (Scheme 6.86). The monosubstituted ethylenes 1-hexene, vinylcyclohexane, allyltrimethylsilane, allyl alcohol, ethyl vinyl ether, vinyl acetate and N-vinyl-2-pyrrolidone furnished [2 + 2]-cycloadducts of the type 419 in yields of 54—100%. Mixtures of [2 + 2]-cycloadducts of the types 419 and 420 were formed with vinylcyclopropane, styrene and derivatives substituted at the phenyl group, acrylonitrile, methyl acrylate and phenyl vinyl thioether (yields of 56-76%), in which the diastereomers 419 predominated up to a ratio of 2.5 1 except in the case of the styrenes, where this ratio was 1 1. The Hammett p value for the addition of the styrenes to 417 turned out to be -0.54, suggesting that there is little charge separation in the transition state [155]. In the case of 6, the p value was determined as +0.79 (see Section 6.3.1) and indicates a slight polarization in the opposite direction. This astounding variety of substrates for 417 is contrasted by only a few monosubstituted ethylenes whose addition products with 417 could not be observed or were formed in only small amounts phenyl vinyl ether, vinyl bromide, (perfluorobutyl)-ethylene, phenyl vinyl sulfoxide and sulfone, methyl vinyl ketone and the vinylpyri-dines. 

Besides chalcones, other types of a,p-unsaturated carbonyls affording five-membered S-heterocycles were cinnamaldehyde, 12, and the a,p-unsaturated methyl ketone 13 and phenyl ketones 14 and 15. However, another phenyl ketone, 16, substituted at the a position or tertiary butyl ketone 17 failed to yield S-heterocycles. 

In the pioneering studies of Melchiorre and Jorgensen and colleagues, a variety of pyrrolidine-derived catalysts was tested (Scheme 2.51) [40]. Whilst modest selectivity was obtained with proline, and unhindered prolinol derivatives, (S)-2-(bis(phenyl)methyl)pyrrolidine derivative, 45c, allowed good conversion and enantio selectivity in the addition of linear aldehydes to methyl-vinyl ketone (MVK) (revalues up to 85%). Cyclic enones as well as -substituted enones afforded no, or perhaps poor, results. 

Tchoubar, B., Sackur, O. Alkaline dehalogenation of 1-chlorocyclohexyl methyl ketone and 1-chlorocyclohexyl phenyl ketone. Transposition into a-substituted cyclohexanecarboxylic acids. Compt. rend. 1939, 208,1020-1022. 

Hexafluoroacetone imine has been prepared by the reaction of hexafluoroacetone with triphenylphosphine imine, by the pyrolysis of N-phenyl-2,2-diaminohexafluoropropane, by the reaction of hexafluorothioacetone with hydrazoic acid, and by the reaction of ammonia and phosphorus oxychloride with hexafluoroacetone. The latter method, which is described here, is the most convenient for it does not require preparation of several intermediates or use of pressure equipment. This method has also been used to prepare the imines of other Huoroketones, including the imines of chloropentafluoroacetone, dichlorotetrafluoroacetone, and perfluorodiethyl ketone. Substitution of methylamine for ammonia in this procedure gives the N-methyl imine. ... 

Gebicki et al. have reported that lH-3H-exchange in o-methyl-substituted phenyl ketones is a valuable tool for probing the formation of transient photoenols. 

Hydroxy Alkyl Phenyl Ketones The basic structures, 2-hydroxy-2-methyl-l-phenyl-1-propanone HAP and 1-hydroxy-cyclohexyl-1-phenyl ketone HCAP, are also well known [17] and still largely used (10.10) and studied [2i,f,18]. The para substitution of the benzoyl group (with an amino, an ether, or a thioether group) drastically changes the electronic transitions but does not significantly affect the reactivity of the derived benzoyl initiating radical. 

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