Cyclo-hexanedione

METHOXY-2,4-CYCLOHEXADlEN-l-YL] -5,5-DIMETHYL-l, 3-CYCLO-HEXANEDIONE]lRON,57, 16 TRICARBONYL [(1,2,3,4,5-n)-2-METH-OXY-2.4-CYCLOHEXADIENE-1-YL ] -IRON(l+)HEXAFLUOROPHOS-PHATE(l-), 57, 107... 

Equation 11.11 Arylation ofthe ethyl vinyl ether of 1,2-cyclo-hexanedione. 

The lumps of the sodium salt of 2,S-dicarbethoxy-l,4-cyclo-hexanedione should be completely reacted before the filtration... 

Hydrolysis, of 2,5-dicarbethoxy-l,4-cyclohexanedione to 1,4-cyclo-hexanedione, 45, 2S of 7,7-dimethoxybicyclo[2.2.1]hep-tene, 48,2S... 

The oxidation of cyclohexanone involves 2-hydroxycyclohexanone and 1,2-cyclo-hexanedione as intermediates.171... 

Considerations of entropies of activation played a major role in a recent discussion of the acid-catalyzed interconversion of 1,2-cyclo-hexanedione and its enol (Bakule and Long, to be published). The reaction is more complex than the usual keto-enol interconversion because the ketone form, but not the enol, is found to be hydrated. 

Mopper, K., Stahovec, W.L., and Johnson, L., Trace analysis of aldehydes by reversed-phase high-performance liquid chromatography and precolumn fluorigenic labeling with 5,5-dimethyl-l,3-cyclo-hexanedione, J. Chromatogr., 256, 243, 1983. 

It is possible to block the ability of LDL to bind to B-100,E receptors in fibroblasts (M14) and liver (C9, K26, W18) by modifying the arginine residues of LDL with cyclohexanedione. In vivo turnover studies using cyclo-hexanedione-modified and unmodified LDL have suggested that about two-thirds of LDL removed from the circulation in normal man is taken up by B-100.E receptors, and one-third by another mechanism (S26). 

Some esters (Eq. 12) [50] and amides (Eq. 13) [52] have also been shown to undergo direct a-arylation. Hallberg et al. reported the arylation of 1,2-cyclo-hexanedione that seems to occur in a different mechanism, possibly via car-... 

Probl mi 27.13 When mesityl oxide, (CH3>2C CHCOCHu is treated with ethyl malonate in the presence of sodium ethoxide, compound M is obtained, (a) Outline the steps in its formation, (b) How could M be turned into 5,5-dimethyl-1,3-cyclo-hexanedione ... 

Aldol and Knoevenagel condensations. The aldol reaction between 1,4-cyclo-hexanedione and aldehydes to give 2-substituted hydroquinones is conducted with LiCl in refluxing p)nidine. Microwave irradiation facilitates Knovenagel condensation using LiCl as catalyst, otherwise NMP is employed as solvent. 

Allenes possessing a hydroxyl group at the allylic position undergo arylation which is accompanied by epoxide formation. A 3-aryl group is readily introduced to 1,2-cyclo-hexanedione and 2-ethoxy-2-cyclohexenone. Ethyleneacetals of aryl methyl ketones are obtained on arylation of hydroxyethoxy vinyl ether. ... 

NTBC (2-(2-nitro-4-trifluoro-methylben2oyl)- 1,3-cyclo-hexanedione) is a chemical initially developed as a herbicide. Animal studies show that NTBC is an inhibitor of... 

Under very similar conditions, then, the tetrol plus 1,4-cyclo-hexanedione was condensed to produce a 70% yield of the corresponding polyspiroketal III. This material III... 

B2N606C3oH34, Borate(2 —), tris[p.-[(l,2-cyclo-hexanedione dioximato)-0,0 ]-diphenyldi-iron complex, 21 112... 

Condensation of the malononitrile (85 R=H or Ar) with dimethone or acetoacetate gave good yields of the 4H-chromene (86) or 4H-pyran (87).98 Another approach to chromenes from aliphatic compounds is provided by condensation of citral with cyclo-hexanediones to yield the reduced chromene (88) which may be aroma-tised in a one-pot process to the 2H-chromene (89).99... 

Aminopyrimidine-5-carboxaldehyde 421 (67CB3664) and 1,3-cyclo-hexanedione react in a 1 2 molar ratio to form 422 in quantitative yield. 

Acetyl-CoA carboxylase (ACC) catalyzes the first step in fatty acid biosynthesis. Owing to its role it has been exploited as an important herbicide target. Two chemical classes, the aryl-oxy-phenoxy-propionate (AOPP or fop) and the cyclo-hexanedione (CHD or dim) herbicides are widely used to control a broad selection of grass weeds in dicot crops and some of them even in cereals or in rice [1, 2]. Their frequent use has resulted in the development of resistance in several grass species [3],... 

The products [Ni(L1815)] to [Ni(L1820)] are obtained by template condensation of sulphur-substituted isothiocarbohydrazides with diacetyl monoxime, 1,2-cyclo-hexanedione monoxime or isonitrosoacetone in the presence of nickel salts in boiling methanol followed by neutralisation with pyridine. Chromatographic separa-... 

Differential herbicide sensitivity at the site of action is a second possible selectivity mechanism, with good precedence in the aryloxyphenoxy and cyclo-hexanedione grass herbicides (2Q, 51). However, several studies now clearly indicate that the inherent sulfonylurea crop selectivities listed in Table 1 are not based on differential sensitivity at the site of action. ALS preparations isolated fix>m crops and weeds are equally sensitive to several selective sulfonylurea herbicides (28.32.33). Although data have not appeared for all of the compounds shown in Table 1, we conclude that differential active site sensitivity is not a general sulfonylurea selectivity mechanism. The clear exceptions to this generalization are the cases of genetically-altered plants (crops and we s) which have acquired through mutation or deliberate transformation a resistant form of the ALS enzyme (see below). 

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