Undecan-6-one

An alternative procedure is to convert the carbonyl compound into the toluene-p-sulphonylhydrazone,12 followed by reduction with either sodium borohydride in acetic acid,13 or with catecholborane, followed by decomposition of the intermediate with sodium acetate or tetrabutylammonium acetate.14 The former method is illustrated by the conversion of undecan-6-one into undecane (Expt 5.6), and the latter by the conversion of acetophenone into ethylbenzene (Expt 6.4, Method B). A feature of these methods is that with a, / -unsaturated ketones, migration of the carbon-carbon multiple bond occurs thus the tosylhydrazone of isophorone gives 3,3,5-trimethylcyclohex-l-ene, and the tosylhydrazone of oct-3-yn-2-one gives octa-2,3-diene. 

To a slurry of undecan-6-one toluene-p-sulphonylhydrazone (5.08 g, 15 mmol) (1) in 50 ml of glacial acetic acid is added sodium borohydride pellets (c. 5.67 g, 150 mmol, 24 pellets) (2) at such a rate that foaming is not a problem (c. 1 hour). The solution is stirred at room temperature for 1 hour and then at 70 °C for 1.5 hours. The solution is then poured into crushed ice, made basic with aqueous sodium hydroxide and extracted with three portions of pentane. The pentane solution is dried and concentrated in a rotary evaporator, and the residue distilled at reduced pressure (Kugelrohr apparatus) to obtain 1.96 g (84%) of undecane. Undecane has b.p. 87 °C/20 mmHg. 

SYNS AMYL KETONE O DIAMYL KETONE DIPENTYL KETONE 6-OXOUNDECANE PENTYL KETONE UNDECAN-6-ONE... 

UNDECANONE see UKSOOO 6-UNDECANONE see ULAOOO UNDECAN-6-ONE see ULAOOO 10-UNDECENAL see ULJOOO... 

The long-chain ketone undecan-6-one (8-207) has a strong fruity smell, but its positional isomer undecan-2-one (8-207) smeU is reminiscent of rue Ruta graveolens, Rutaceae). The smeU of undecan-4-one (8-207) lies between these two extremes. 

Startg. mesylate refluxed 7 hrs. under Ng in triethylaniine-pyridine -> 2/ -carbo-methoxy-7,7-dimethyltricyclo[6.2.1.0t 5]undecan-6-one. Y 91%. Also rearrange-... 

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