5-methylhexane-2-one

Plot a graph of logi0f against the molecular weight or alternatively the carbon number (i.e. the number of carbon atoms in the molecule) of the ketone. Estimate the retention time of a ketone containing six carbon atoms and check your result by a suitable injection. Finally examine the chromatographic behaviour of 3-methylbutan-2-one, 4-methylpentan-2-one and 5-methylhexan-2-one. 

A laser flash study of the photoreactions of hexan-2-one and 5-methylhexan-2-one has provided evidence for the existence of the triplet 1,4-biradicals produced by the y-hydrogen abstraction typical of Norrish Type II reactivity. The photochemical behaviour of the alkanone, nonan-5-one, in urea inclusion compounds has been studied. In solution, irradiation of nonan-5-one yields hexan-2-one, propylene, and two cyclobutanols. In the clathrate, the fragmentation products were essentially the same but only one cyclobutanol was observed. The cyclization fragmentation ratio was established as 0.67, compared with 0.32 in methanol. The authors suggest that the CIS-cyclobutanol has less stringent rotational requirements and that it is this isomer (43) which is formed in the clathrate. 

D.21) 2-Hexanone, 5-methyl-, 5-methylhexan-2-one, isopentyl methyl ketone, isoamyl methyl ketone 1110-12-3]... 

Beilstein Handbook Reference) BRN 0506163 EINECS 203-737-8 2-Hexanone, 5-methyl- HSDB 2885 Isoamyl methyl ketone Isopentyl methyl ketone Ketone, methyl isoamyl 2-Methyl-5-hexanone 5-Methyl-2-hexanone 5-Methylhexan-2-one Methyl isoamyl ketone Methyl isopentyl ketone MIAK UN2302. Liquid bp = 144 d = 0.888 hn = 176.188,192,196 nm (gas) slightly soluble in H2O. soluble in CCI4, very soluble in MezCO, CeHe, freely soluble in EtOH, Et20. 

Synonyms Isoamyl methyl ketone Isobutylacetone Isopentyl methyl ketone Ketone, methyl isoamyl 2-Melhyl-5-hexanone 5-Methyl-2-hexanone 5-Methylhexan-2-one Methyl isopentyl ketone MIAK Classification Saturated aliphatic ketone Empirical C,HmO Formu/a CH,COC2H,CH(CH,)2... 

Methyl-5-hexanone 5-Methyl-2-hexanone 5-Methylhexan-2-one. See Methyl isoamyl ketone... 

FIGURE 14.17 Mass spectrum of 5-methylhexan-2-one. The peak at mjz = 58 is due to McLafferty rearrangement. The abundant peak at m/z = 43 is due to a cleavage at the more highly substituted side of the carbonyl group. Note that the peak due to the molecular ion is very small. 

In addition to the already mentioned acyloins, food products contain numerous other odorous a-hydroxyketones. For example, 3-hydroxypentan-2-one has ben identified in cheeses, durian, wines, sherry, asparagus, honey, tea, butter and soy sauce, 2-hydroxypentan-3-one in cheeses, durian, coffee, wine, sherry honey, butter and soy sauce, 2-hydroxyhexan-3-one in wine, 4-hydroxyhexan-3-one in durian and tea, 3-hydroxy-5-methylhexan-2-one in cheeses, 3-hydroxyoctan-2-one in beef and heated mutton fat, 5-hydroxyoctan-4-one in cocoa and 3-hydroxy-4-phenylbutan-2-one in wine, sherry and honey. 

Dimethylpentan-3-one Heptan-2-one Heptan-3-one Heptan-4-one 5-Methylhexan-2-one Butyl propanoate... 

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