From P-diketones

A synthetically useful reaction known as the Michael reaction, or Michael addition, involves nucleophilic addition of carbanions to a p unsaturated ketones The most common types of carbanions used are enolate 10ns derived from p diketones These enolates are weak bases (Section 18 6) and react with a p unsaturated ketones by conjugate addition... 

Stabilized anions exhibit a pronounced tendency to undergo conjugate addition to a p unsaturated carbonyl compounds This reaction called the Michael reaction has been described for anions derived from p diketones m Section 18 13 The enolates of ethyl acetoacetate and diethyl malonate also undergo Michael addition to the p carbon atom of a p unsaturated aldehydes ketones and esters For example... 

Alkynic ketones can be prepared in good yields from p-diketones using a,a-difluoroalkylamines and KF (Scheme 53). 00... 

Acrylonitrile (2) has also been used for heterocycle formation from p-diketone substrates. Conjugate addition of 185 to acrylonitrile produced 186 with previously reported conditions,2 and cyclization under hydrolytic conditions generated the corresponding lactam 187 (Scheme 15).65 Dissolving metal reduction provided the trans ring fused product 188, which was subsequently converted to 189. Reduction of 189 completed the synthesis of the Lycopodium alkaloid ( )-Na-methyl-A p-acetylphlegmarine (190) as a mixture of 4 diastereomers. 

Palladium-carbon sulfuric acid Ketones from p-diketones 61. 0... 

Pyrazoles from p-diketones and hydrazines under ultrasonication... 

The preparation and hydrolysis of imines can be considered parallel to those of acetals. Such a process is used to prepare a pyrazole ring from p-diketones derived from fatty esters (Eq. 33). No catalyst is necessary. 

GUARESKY-THORPE Pyridone Synthesis Synthesis of 2-pyridones from p-diketones and activated amides (see 1st edition). 

Stryckmans, O., Segato, T., Duvigneaud, P.H. Formation of MgO films by ultrasonic spray pyrolysis from P-diketonate. Thin Solid Films 283, 17-25 (1996)... 

Pentene-l,5-diones (e.g., 156), the products of a Knoevenagel condensation of two molecules of 1,3-diketone, are intermediates in the formation of 3-acylpyridines 157 from P-diketones and NH3 ... 

Furanose annelation, as illustrated in Scheme 22, provides efficient access to chiral furanoids such as 105 and 106. A variety of stabilised carbon nucleophiles has been employed, including dianions derived from p-diketones and other p-ketoesters, and it is noteworthy that nucleophilic displacement of triflate is faster than epoxide ring opening. "... 

When enol esters derived from P-diketones are used in the photocycloaddition reaction with an alkene (de Mayo s reaction), a hydrolysis of the ester group of the cyclobutyl intermediate allows opening of the cyclobutane ring by a retro-Aldolization process and the formation of medium-ring cychc compounds. Similarly, hydrolysis of the cycloadduct obtained by irradiation of 3-carbomethoxycyclopentenone in the presence of a P-ketoester allowed facile access to ( )-norasteriscanoHde (Scheme 18). 

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