164. β-Cholesterol oxide

Baxter, R. A.; Spring, F. S.

doi:10.1039/jr9430000613

Cited by 17 publications

(17 citation statements)

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“…(6) [31] und 9,2 g (50 mmol) Imidazol-4,5-dicarbonsaure-dimethylester (7) [32] ( d x d , J2',3'=5,5, €I-C(2')); 6,03 (dxd, J3,.4r=6,0. H-C(3')); (CDC13): 6,66 (d, Rohes Sily1deriva.t 9 (aus 18,4 g (100 mmol) 7) und 50.5 g (100 mmol) 6, gelost in 500 ml Athylenchlorid wurde unter Riihren und Eiskuhlung tropfenweise mit einer Losung von 11,8 ml (100 mmol) Zinntetrachlorid in 250 ml Athylenchlorid versetzt, 48 Std.…”

Section: I)unclassified

Nucleosid‐Synthesen in der Imidazolreihe

Wyss

Fischer

1978

Helvetica Chimica Acta

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SummaryThe acid-catalyzed fusion of dimethyl imidazole-4,5-dicarboxylate (7) with I-O-acetyl-2,3,~-tri-O-benzoyl-~-~-ribofuranose (6) provided dimethyl 1 -(2,3,5-tn-O-benzoyl-~-~-ribofuranosyl)imidazole-4,5-dicarboxylate (11) as the major product together with some a-anomer (13). The 8-anomer (11) was obtained as the only product when the trimethylsilyl derivative (9) of 7 was condensed with 6 in the presence of stannic chloride. Nucleoside 11 was treated with ammonia, and various primary amines to provide l-~-~-ribofuranosylimidazole-4,5-dicarboxarnide (5) and N , N'-disubstituted dicarboxamides (18-26) respectively. The synthesis of 1 -a-(33) and 1 -~-~-arabinofuranosylimidazole-4, 5-dicarboxamide (34), is also described. The conformation of 5, as studied by 'H-and I3C-NMR.-spectroscopy, was shown to be very similar to that of adenosine.The oxidation of the 2', 3'-O-isopropylidene derivative (15) of 5 with potassium permanganate or chromic oxide, followed by deprotection, or the direct oxidation of 5 with oxygen in the presence of platinum catalyst, led to the corresponding 5'-carboxylic acid 36. This was further converted into esters (37 and 38) and arnides (39-42).Treatment of some nucleosides with fuming nitric acid in oleum at -30" yielded the nitric acid esters 43-51. Beside the nitration of their sugar residues, one of the imidazolecarboxamide functions in nucleosides 46-51 and both N-methylcarboxamide functions in 44 were nitrated. Finally, reaction of the N , "-dimethyl-N, N'-dinitrodicarboxamide 44 with alkyl-und aralkylamines, afforded the N, N'-dialkyl-and N , N'-diaralkyldicarboxamides 52-56.

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Section: I)unclassified

Nucleosid‐Synthesen in der Imidazolreihe

Wyss

Fischer

1978

Helvetica Chimica Acta

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“…As a rule, however, one of these forms preponderates or may be produced exclusively. The well-known fission reactions of the two cholesteryl oxides using water, hydrochloric acid, and glacial acetic acid (32,33) as well as the above mentioned hydrogena- sion of the a-oxide ring, therefore, occurs preferably or only at C-6 and of the �-oxide ring at C-5, as is indicated in the formulae. In acco r dance w ith this formulation both oxides (IX) and (VII) (or their respective acetates) yield the same trans-triol (XXVIII) (or its 3-monoacetate) when hydrolysed with water in dioxane (11).…”

Section: XIX Xxmentioning

confidence: 95%

The Chemistry of the Steroids

Reichstein

Reich

1946

Annu. Rev. Biochem.

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“…A mixture of dimethyl imidazole-4,5-dicarboxylate (3) [7,8] (1.0 g, 5.4 mmoles) and potassium carbonate (0.75 g, 5.4 mmoles) in 40 ml of anhydrous DMF was stirred at 100 °C for 3 hours. A solution of diethyl 2-p-toluenesulfonyloxyethoxymethanephosphonate [9] (2.75 g, 7.5 mmoles) in 5 ml of dry dimethylformamide was added, and the mixture was continued to stir for 48 hours at 100 °C.…”

Section: Dimethyl 1-(2-diethoxyphosphonylmethoxyethyl)-45-imidazoledmentioning

confidence: 99%

“…We report here the synthesis of a novel ring-expanded ("fat") analogue of PMEG (fPMEG), 6-amino-4,5-dihydro-8H-1-(2-phosphonylmethoxyethyl)imidazo [4,5-e ]- [1,3]diazepine-4,8-dione (7).…”

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confidence: 99%