Dialkyl acetone-1,3-dicarboxylates

Dialkyl Acetone-1,3-Dicarboxylates and their Mono-and b/s(Dimethylamino) methylidene Derivatives in the Synthesis of Heterocyclic Systems... 

TRANSFORMATIONS OF DIALKYL ACETONE-1,3-DICARBOXYLATES AND THEIR (DIMETHYLAMINO) METHYLIDENE DERIVATIVES... 

Using dialkyl acetone-1,3-dicarboxylate 323 in place of the traditional p-ketoesters in a conventional Biginelli condensation (HCl or p-TsOH) furnished 324, along with conformationally restricted tricyclic intramolecular Michael addition product 325 (Scheme 124) (07JHC455, 08TL3520). 

Piperidones are important piperidine derivatives. Other methods are available for their synthesis, e.g. the Dieckmann cyclization of the diesters 1, the Thorpe-Ziegler cyclization of the dinitriles 2 and cyclization of dialkyl ketones or acetone dicarboxylic esters with aldehydes and primary amines in a Mannich reaction ... 

Dialkyl Acetone-13-Dicarboxylates in the Synthesis of Heterocyclic Systems... 

Figure 1 Heterocycles obtained from dialkyl acetone-13-dicarboxylates and their (dimethylamino)methylidene derivatives.

Dialkyl acetone-1 -dicarboxylates 1 were transformed with DMFDMA by heating in ethanol into dialkyl l,5- is(dimethylamino)-3-oxo-penta-l,4-diene-2,4-dicarboxylates 52 in good yields. They were treated with ammonia, hydrazine, primary aliphatic, aromatic or heterocyclic amines to form dialkyl 1-substituted 4-oxo-l,4-dihydrop5u--idine-3,5-dicarboxylates 53 and 54.1,4-Diaminobenzene reacts with 52 in a 1 2 molar ratio to produce l,4-bis[3,5-fcis(alcoxycarbonyl)-4-oxo-l, 4-dihydropyridin-l-yl]benzene 55 in 57% yield. Hydrazine and mono-substituted hydrazines afforded 1-amino-1,4-dihydro-4-oxop5uidines 54 (00H2033) (Scheme 20). 

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