The condensation of aliphatic aldehydes with methyl P-methylglutaconate gives alkylidene glutaconic acids (111) and carboxy-&lactones (IV). Shortchain and branched-chain aldehydes give diacids (111); longer chain and unbranched aldehydes give carboxylactones (IV). Decarboxylation of these products gives the dienonoic acids VI and &lactones V. The lactones can be hydrolyzed to the corresponding acids and the preferred ...
