Action of Zinc Alkyl on Acyl Chlorides in certain proportions

Reaction XXH. (c) Action of Zinc Alkyl on Acyl Chlorides in certain proportions.—The preparation of alcohols by this method has already been discussed (Reaction XV.). By using only 1 mol. of zinc alkyl to 2 mols. of acid chloride, the reaction can be stopped at the intermediate ketone stage. In the Grignard reaction with acid chlorides, it has not been found possible to do this owing to the greater reactivity of the Grignard compounds. 

Reaction XXHI. (a) Condensation of Ethyl Formate with certain Keto-Compoonds under the influence of Sodium Ethoxide (Claisen). (A., 283, 

)—This condensation is undergone by all compounds containing the group—CH2—CO—. It follows the same lines as the other ester-ketone condensations (see pp. 142 et seq.). 

The compounds separate from the condensation as sodium salts. From the simple ketones, the compound formed is not stable and undergoes change on precipitation from its sodium salt. The formation of a hydroxymethylene compound is used as proof of the presence of the group—CH2—CO—in camphor. The following preparation shows the details of the method. 

90 gms. (excess) of camphor are dissolved in toluene which has been freed from water by standing over calcium chloride, and to this solution are added 6 gms. of sodium wire. To the well-cooled mixture 19 gms. (1 mol.) ethyl formate are added, when it is set aside in an ice chest for 24 hours. It is then poured into ice-water, and after vigorous shaking the aqueous layer removed. After acidifying with acetic acid, and then extracting with ether, the ethereal extract is dried over calcium chloride. The ether is removed by distillation, and the residue, after being placed in a basin, is allowed to evaporate slowly at ordinary temperature. The oil 

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