The Synthesis of Ketones of the Type RCOCHR, from a,a

3163

SYNTHESIS OF KETONES FROM a,a-DISUBSTITUTED P-KETOESTERS

Nov., 1941

[CONTRIBUTION FROM

THE

DEPARTMENT OF CHEXISTRY OF DUKEUNIVERSITT ]

The Synthesis of Ketones of the Type RCOCHR, from a,a-Disubstituted p-Keto Esters. An Extension of the Acetoacetic Ester Type of Ketone Synthesis’ BY BOYDE. HUDSON, JR., The classical acetoacetic ester synthesis of ketones, involving the mono- and di-alkylation of ethyl acetoacetate and the subsequent “ketonic” hydrolysis, gives only the methyl ketones, CH3COCHzR and CH3COCHR2. Higher acyl acetates, RCbCH2COOC2H5,might be alkylated and then cleaved to give the ketones, RCOCHzR and RCOCHR2, but most of these 6-keto esters are rather difficult to prepare and their di-alkylation is sometimes difficult to effect. Symmetrical ketones of the type RCHzCOCHzRhave been prepared2 by the self-condensation of the esters, RCH2COOC2H5, and hydrolysis of the resulting 0-keto esters, RCH2COCHRCOOC2H5. The latter keto esters might be alkylated and then

AND

CHARLES R . HAUSER

RC