2,4-Pen tanedione

A 200 mM phosphate-buffered solution, pH 6.9 (100 mL), containing 3-allyl-2,4-pen-tanedione (700 mg, 50 mmol), glucose (2.16 g, 120 mmol), NADPH (45 mg), glucose dehydrogenase (50 mg) and KRED-108 (70 mg) was stirred at room temperature for 24 h, until GC analysis of crude extracts showed complete reaction. Periodically, the pH was readjusted to 6.9 with NaOH (2m). 

Much more studied is the reaction of /8-dicarbonyl compounds with 2-amino-2-deoxyaldoses in particular, with 2-amino-2-deoxy-D-glu-cose (55), both in neutral and alkaline medium. In neutral methanol or aqueous acetone, 2-amino-2-deoxy-D-glucose reacts with 2,4-pen-tanedione to give52 54 3-acetyl-2-methyl-5-(D-arabino-tetrahydroxy-butyl)pyrrole (56a), and, with ethyl acetoacetate,55 the pyrrole 56b. Similar (tetrahydroxybutyl)pyrroles have been prepared from other /3-keto esters, such as ethyl 3-oxohexanoate, ethyl thiolacetoacetate, and diethyl 3-oxopentanedioate.53,56,56a... 

A variety of metal complexes containing fluorinated aminoalkoxy ligands have been prepared by template reactions involving amines and fluorinated 2,4-pen tanediones. 47,148... 

Union Carbide and Carbon Corporation technical 2,4-pen-tanedione was used without purification. 

The many satisfactory procedures which have been published for the preparation of metal derivatives of 2,4-pen-tanedione (acetylacetone) are not always successful when applied to other 8-diketones. Thus, poor yields of impure product are obtained with attempts to prepare the... 

Tris(2,4-pentanedionato)molybdenum(III) is a dark purple crystalline solid, m.p. 228 to 230°. It reacts rapidly with atmospheric oxygen to form a diamagnetic brown product, m.p. 284 to 285° (decomp.), containing pentaposi-tive molybdenum. This oxidation state is determined by dissolution in concentrated hydrochloric acid to produce a solution which has the same absorption spectrum in the visible region as green oxopentachloromolybdate(V), by cerimetric titration of this concentrated hydrochloric acid solution after chloroform extraction of the liberated 2,4-pen-tanedione, and by independent synthesis from a brown... 

Problem 23.15 What product would you obtain from a base-catalyzed Michael reaction of 2,4-pen-tanedione with each of the following a,j8-unsaturated acceptors ... 

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