3.3- Dimethyl-2-butanone, alkylation

Hydroxy-2-butanone (alkyl ketone) 3-Hydroxy-4,5-dimethyl-2(5H)-furanone (= Sotolon) (furanone)... 

Derivatives. Small amounts of alkyl quiaolines are present ia the tars resulting from the carbonization and Hquefaction of coal (111). Good yields of 4-methyl quinoline, 4,6-dimethyl quinoline [826-77-7], and 4,8-dimethyl quinoline [13362-80-6] are obtained from 4-(diethylamino)-2-butanone and the appropriate aniline. This approach is a promising addition to the traditional syntheses discussed eadier (112). Vlaylacetylene reacts with mercuric chloride and either aniline or -toluidine to yield 4-methyl- and 4,6-dimethyl quinoline, respectively (113). 

Material accountability (the sum of recovered chloropinacolone, methyl pivaloyl acetate, and pinacolone) with the active Pd monophosphine and carbene complexes was in the range of 92-99% without accounting for impurities present in the starting chloropinacolone. A GC-MS examination of several product mixtures was undertaken to see if there were any additional, unanticipated by-products. The only additional material identified was a-methoxy pinacolone (l-methoxy-3,3-dimethyl-2-butanone). This compound was formed by methanolysis of the starting a-chloropinacolone and appears to be formed by a mixture of catalyzed and uncatalyzed processes Since this product was not anticipated, it was not quantified but represents the majority of, if not the only, remaining volatile product. No attempt was made to determine the presence of any quaternary ammonium salt formed by similar alkylation of the amine base by a-chloropinacolone. 

Asymmetric reduction of ketones. Ipc BCl is somewhat superior to B-3-pin-anyl-9-borabicyclo[3.3.1]nonane (12, 397) for enantioselective reduction of alkyl aryl ketones at normal pressures to (S)-alcohols. In general, optical yields are 78-98%. It is also useful for asymmetric reduction of ketones in which one alkyl group is tertiary. Thus 3,3-dimethyl-2-butanone is reduced in 95% ee at 25°.1... 

Alkyl ethers of benzoin Benzil dimethyl ketal 2-Hydroxy-2-methylphenol-l-propanone 2,2-Diethoxyacetophenone 2-Benzyl-2-At, V-dimethylamino- l-(4-morpholinophenyl) butanone Halogenated acetophenone derivatives Sulfonyl chlorides of aromatic compounds Acylphosphine oxides and bis-acyl phosphine oxides Benzimidazoles... 

In the studies of the reactions of l-hydroxy-2-propanone and l-hydroxy-2-butanone and ammonium sulfide, despite four possible intermediates were predicted, only two intermediate compounds were tentatively identified by GC/MS in our study. The mass spectral data of these compounds showed very distinctive base peak p attem (Table I). These results agreed with results from previous study of five different 2-alkyl-2,4,5-trimethyl-2,5-dihydrooxazolines (7) which showed same mass spectral fragmentation pattern (m/z = 112) of same types of intermediate con5>ounds. Further study of GC/MS-CI results suggested their molecular weights and as the results, they were tentatively identified as 2-(1 -hydroxymethyl)-2,4-dimethyl-3-oxazoline, 2-( 1 -hydroxymethyl)-2,4-... 

Alkyl alkyl ketones have also been enantioselectively hydrosilylated with rhodium catalysts containing phosphorus-based ligands. The results were similar to those from the reactions of 1-phenylethanone3-5. The highest value was 72% ee for the hydrosilylation of 3,3-dimethyl-2-butanone to (S)-3,3-dimethyl-2-butanol with diphenylsilane using a rhodium/Amphos system, based on the optically active aminophosphane ligand Amphos22. 

The preparation of tebufenpyrad and tolfenpyrad (see below) are outlined in Scheme 28.3.4. The pyrazole ring is prepared from a Claisen condensation of 2-butanone with diethyl oxalate followed by treating the resulting acylpyruvate with hydrazine [45, 46]. The pyrazole ring is then alkylated with dimethyl sulfate at 50-60 °C without base to give, selectively, the l-methylpyrazole-5[Pg.893]

As noted, the pK of the a-proton in acetone (2) is about 20. In other ketones, different groups attached to the a-carbon lead to a different pKg for the a-proton, depending on whether the group is electron releasing or electron withdrawing relative to the a-carbon. With a focus on the proton marked in red in the illustration, 3,3-dimethyl-2-butanone (10), for example, has a pKg of about 20.8 and 11 has a pKg of about 21.3. These two compounds allow a direct comparison of the influence of an alkyl group on the a-carbon when compared with acetone. 

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