Reactions of dianions of carboxylic acids with esters and .alpha.,.beta.-unsaturated esters, nitriles, and aldehydes

Trifluoromethyl Ketones from Enolizable Carboxylic Acids via Enediolate Trifluoroacetylation/Decarboxylation

“…The procedure was also applied to the synthesis of nitro compounds by quenching with n -propylnitrate. We postulated the analogous trapping of a carboxylic acid dianion with ethyl trifluoroacetate would give an intermediate α-trifluoroacetyl carboxylate that would readily decarboxylate on acidification to give a trifluoromethyl ketone . This proved to be the case, and herein we present the scope of this reaction.…”

Mastering .beta.-Keto Esters

“…The same concept has been then applied by Trost68 using phenylthiopropionyl chloride (42) as the acylating agent and affecting the elimination reaction after the oxidation of sulfide to sulfoxide with sodium metaperiodate. In 1978, Taylor and Turchi69 applied this procedure to a great number of acyl halides.…”

Silyl enol ethers and silyl ketene acetals

“…10 per cent HMPA to the THF solution results in smooth reaction 54 . Diethyl oxalate reacts somewhat differently, to produce the isomeric tetraoxyalkenes (28). Disubstituted malonates cannot, of course, react in a similar manner.…”