Hydroxymethylene diazo compounds

The HC1 generated in this reaction destroys one equivalent of diazomethane. This can be avoided by including a base, such as triethylamine, to neutralize the acid.74 Cyclic z-diazoketones, which are not available from acyl chlorides, can be prepared by reaction of an enolate equivalent with a sulfonyl azide. This reaction is called diazo transfer 5 Various arenesulfonyl azides76 and methanesulfonyl azide77 are used most frequently. Several types of compounds can act as the carbon nucleophile. These include the anion of the hydroxymethylene derivative of the ketone78 or the dialkylaminomethylene derivative of... 

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... 

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