Ceric ammonium nitrate, and

Silyi enol ethers can be dimerized to symmetrical 1,4-diketones by treatment with Ag20 in DMSO or certain other polar aprotic solvents." The reaction has been performed with R , R = hydrogen or alkyl, though best yields are obtained when r = r = H. In certain cases, unsymmetrical 1,4-diketones have been prepared by using a mixture of two silyi enol ethers. Other reagents that have been used to achieve either symmetrical or cross-coupled products are iodosobenzene-Bp3-Et20," ceric ammonium nitrate," and lead tetraacetate." If R =0R (in which case the substrate is a ketene silyi acetal), dimerization with TiCU leads to a dialkyl succinate (34, r =0R)." ... 

Grafting and networking may modify the mechanical, chemical, and functional properties of polymers and enhance their utilization for some purposes, such as for water treatment (Kumar and Verma, 2007 Mishra et al., 2003). Psyllium derivatives were prepared by grafting acrylonitrile onto psyllium molecules using a ceric ammonium nitrate and nitric acid system (Mishra et al., 2003). The resulted grafted psyllium samples were not soluble in commonly used solvents or their combinations. In 2007, methacrylic acid derivatives of psyllium were prepared using ammonium persulfate as initiator and cross-linked using N,N-methylenebisacryla-mide as the crosslinker (Kumar and Verma, 2007). The modified psyllium... 

Snider and Kwon use either cupric triflate and cuprous oxide or ceric ammonium nitrate and sodium bicarbonate as single-electron oxidants to convert d,s- and ,C-unsaturated enol silyl ethers 9 stereoselectively to the tricyclic ketones 14 in excellent yields [83, 84]. Based on comparison with other experimental data and literature results, the authors try to distinguish between several possible intermediates and propose the following mechanism with a very electrophilic radical cation 10 as the key intermediate. 

The synthesis of antiviral spiro-(3-lactam 51 begins with the benzylation of isatin 45 to give 1-benzylisatin 46, which affords Schiff s base 47 on reaction with anisidine in ethanol. The Schiff s base 47 on treatment with methoxyacetyl chloride by the chloride-imidate cycloaddition [85] route afforded a mixture of spiro E- and Z-azetidin-2-ones 48 and 49, which were separated by chromatography. The (Z)-N-arylazetidin-2-one 49 was further converted to desired 4-spiro-(3-lactam 51 by treatment with ceric ammonium nitrate and subsequently with tetrabutylammonium bromide in THF in the presence of pulverized KOH (Scheme 13). 

Antioquine (466), C37H40N206, mp 197°C [a]D +214° (c 0.9, CHC13), was isolated from a sample of Pseudoxandra aff. lucida Fries (Annonaceae) collected in Colombia. Structure proof was by spectral characterization of the O,O-diacetate, the 0,0-dimethyl ether, and the 7-O-methyl ether, and by degradation of derivatives with KMn04/Me2C0, with ceric ammonium nitrate, and with Na/NH3 (551). 

The biomaterial was dispersed in a definite amount of water. Ceric ammonium nitrate and nitric acid are then to be added slowly to the reaction mixture. Then, the monomer acrylic acid should be added drop wise to the reaction mixture. The reaction flask is to be placed in a water bath at 10-85°C for various time periods under stirring by a magnetic stirrer. After a definite time period, the reaction mixture is to be filtered and the homo-polymer should be removed with excess water. The grafted sample is to be dried to a constant weight and used for sorption studies. From the increase in weight of the biomaterial, the percentage of grafting should be calculated as follows ... 

Conjugate addition of alcohols to conjugated esters, using ceric ammonium nitrate and LiBr, gave the corresponding a-bromo-p-alkoxy ester. ... 

Benzylic compounds, such as ethylbenzene, react with alkyl nitriles, ceric ammonium nitrate, and a catalytic amount of Al-hydroxysuccinimide to give the Ritter product, the amide. ° °... 

In the third approach, shown in Scheme 7.3.8, a glucose derivative was converted to an epoxide via hydrolysis of the acetonide followed by tosylation of the terminal hydroxyl group and treatment with sodium hydride. Subsequent removal of the PMB group with ceric ammonium nitrate and treatment with p-toluenesulfonic acid effected cyclization to the pyranoside. 

A method for the separation of acetals from the parent hydroxylated compounds has been described by Barnett and Kent. Paper made of cellulose acetate was used with 3 2 (v/v) methanol-water for separation, and zones were detected either with (2,4-dinitrophenyl)hydra-zine or with acidified potassium permanganate. The limit of detection (of l,2 5,6-di-0-isopropylidene-a-D-glucofuranose) is about 150 ixg. Later, Bird introduced the combination of ceric ammonium nitrate and silver nitrate sprays as detection reagents specific for acetals of carbohydrates. By this technique, the limit of detection (of 1,2 5,6-di-O-isopropylidene-a-D-glucofuranose) is 8-12 fig,... 

Hiroshi S, Kozuo S, Takeshi T (1962) Analysis of opium alkaloids and allied compounds. XV. Colorimetric determination of dihydrocodeine by ceric ammonium nitrate and 2,4-dinitrophenylhydrazine. Yakugaku Zasshi 82 1684-1687 Hodges CC, Rapoport H (1982) Morphinan alkaloids in callus cultures of Papaver somniferum J Nat Prod 45 481-485... 

A different study generated the lithium imine of 2.118 and condensed it with ester 2.119 to give 2.120. Deprotection of the lactam nitrogen with ceric ammonium nitrate and acid hydrolysis led to formation of 3-amino-2-hydroxy-5-methylhexanoic acid, 2.727.57... 

Until recently, noncatalytic stoichiometric oxidations of arenes with toxic inorganic reagents, such as CrOj and K Cr O., MnO and KMnO, OsO, Pb(OAc), TllNOj), nitric acid, ceric ammonium nitrate, and some others, were the main route for the production of oxygenated aromatic compounds [1, 2, 6, 51]. A classic example is the manufacture ( 1500t/year) of vitamin via stoichiometric oxidation of 2-methylnaphthalene (MN) with carcinogenic CrO in sulfuric acid (Eq. 14.14) [52]. 

Acetone containing trfl/2j-l,2-di(carbazol-9-yl)cyclobutane mixed with methanol containing ceric ammonium nitrate, and the product isolated immediately -> 1,4-di(carbazol-9-yl)-l,4-dimethoxybutane. Y 92%. Also oxidation with tris-(p-bromo-phenyl)ammoniumyl hexachloroantimonate, an amminium salt radical (s. Synth. Meth. 12, 960), s. P. Beresford, M. C. Lambert, and A. Ledwith, Soc. (C) 1970, 2508. 

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