2,4-Pentanedione, with sodium amide

Pentanedione, with sodium amide and diphenyliodonium chloride to give 1-phenyl-... 

The straightforward construction of substituted pyrone 4 proceeded as follows (see Scheme 6c). Alkylation of the monoanion of 2,4-pentanedione (8) with methyl iodide furnishes 3-methyl-2,4-pentanedione. Conversion of this substance into the corresponding dianion with sodium amide followed by selective carboxylation of the more basic site provides intermediate 7. Pyrone 4 is obtained after cyclization with l,l -carbonyldiimidazole and methylation of the resulting enol with dimethyl sulfate. 

Diphenyliodonium chloride, with 2,4-pentanedione and sodium amide to give 1-phenyl-2,4-pentanedione, 51,128... 

Silver fluoborate, reaction with ethyl bromide in ether, 46, 114 Silver nitrate, complexing with phenyl-acetylene, 46, 40 Silver oxide, 46, 83 Silver thiocyanate, 45, 71 Sodium amide, in alkylation of ethyl phenylacetate w ith (2-bromo-ethyl)benzene, 47, 72 in condensation of 2,4-pentanedione and 1 bromobutane to give 2,4-nonanedione, 47, 92 Sodium 2 ammobenzenesulfinate, from reduction of 2 mtrobenzenesul-finic acid, 47, 5... 

Sodium, with l-bromo-3-chloro-cyclobutane to give bicyclo [l.l.O]butane, 51, 55 Sodium amalgam, 50, 50, 51 Sodium amide, with 2,4-pentane-dione and diphenyliodonium chloride to give l-phenyl-2, 4-pentanedione, 51, 128 Sodium azide, 50, 107 with mixed carboxylic-carbonic anhydrides, 51, 49 Sodium borohydride, reduction of erythro-3-methanesulfony-loxy-2-butyl cyclobutanecar-boxylate, 51, 12 reduction of 2-(1-phenylcyclo-pentyl)-4,4,6-trimethyl-5,6-dihydro-1,3(4H)-oxazine to 2-(1-phenylcyclopentyl)-4,4, 6-trimethyltetrahydro-l,3-oxazine, 51, 25 Sodium cyanoborohydride, used... 

Sodium amide, in alkylation, of di-phenylmethane, 48, 80 of ethyl phenylacetate with (2-bromoethyl)benzene, 47, 72 in condensation of 2,4-pentanedione and 1-bromobutane to give 2,4-nonanedione, 47, 92... 

When 1-phenyl-2,4-pentanedione is doubly deprotonated with potassium amide in ammonia, the ensuing aldol reaction with benzophenone gives the expected aldol (19). However, if sodium amide is employed to generate the dianion, the reaction product with benzophenone is the dihydro-7-pyrone (20 equation 36). This result suggests the intermediacy in the latter reaction of a dianion involving the benzyiic position. Further study of this interesting reaction is warranted. 

Many examples of 4- or 5-acetyl-1,2,3-triazoIes have been prepared and a number of methods developed. For example, the addition of phenyl azide to acetylphenylacetylene (Eq. 14) gives an excellent yield, and both isomeric products are obtained. The reaction of sodium azide with /3-acetylstyrylsulfones proceeds in good yield (Eq. 15). The diacetyl phenylhydrazone 5.1-12 is smoothly converted to a 1,2,3-triazole under novel conditions that deserve further exploration (Eq. 16). The heterocyclic azide 5.1-13 reacts with 2,4-pentanedione under basic conditions (. 17). The treatment of the amides 5.1-14 with a Grignard reagent produces... 

The 7-benzyl derivative of XII-53 (W-55) prepared from the sodium salt of 5-phenyl-l, 3-pentanedione, potassium amide, and methyl benzoate, was not isolated but was converted to S-benzyl-6-phenyl4-pyridone with ammonia in ethanol. " ... 

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