Cyclohexanone, 2-hydroxymethylene-, preparation

Hydroxymethylene)cyclohexanone was prepared from cyclohexanone2 and was freshly distilled before use. 

In addition to previously described syntheses4-5 by diazo group transfer with deformylation,6 2-diazocyclohexanone has been prepared by two variants of this method. In one, the reaction of 2-(hydroxymethylene)cyclohexanone with -toluene-sulfonyl azide is carried out in ether/diethylamine, and an enamine is assumed to be formed as an intermediate 7 in the other, the sodium salt of the hydroxymethylene compound was treated with the lithium salt of p-carboxybenzenesulfonyl azide... 

Sometimes acid anhydrides may be used as acylating reagents. The mixed anhydride of formic and acetic acid reacts with the enamines prepared from cyclohexanone to give 50% of hydroxymethylene-cyclohexanone.212 An intramolecular acylation with an ester (70) has also been reported.249... 

Toluenesulfonyl azide was prepared from jj-toluene-sulfonyl chloride and sodium azide. The submitters found that when somewhat less than the stoichiometric quantity of -toluenesulfonyl azide is used, 2-diazocyelohexanone is obtained free of azide the excess 2-(hydroxymethylene)-cyclohexanone is readily removed in the alkaline workup. The crude product obtained by the checkers, however, contained -toluenesulfonyl azide (Note 5). 

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See also in sourсe #XX -- [ , ]

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