The preparation and dienone–phenol rearrangement of androsta-2,5-diene-4,17-dione
作者:James R. Hanson、David Raines、Steve G. Knights
DOI:10.1039/p19800001311
日期:——
The preparation of androsta-2,5-diene-4,17-dione from dehydroisoandrosterone is described. Its dienone–phenolrearrangement, in the presence of hydrobromic acid and glacial acetic acid, affords 1-methyl-4-hydroxyestra-1,3,5(10)-trin-17-one.
2-Dimethylaminomethylestrone (Ia) and the 4-isomer (IIa) were obtained from the Mannich product of estrone. Methiodides of I'a-c and II'a-c were treated with alcoholic alkali to give 2-and 4-alkoxymethylestrogens in good yields. Methylation in the usual manner of I and II failed, but reaction of I and II with dimethylsulfate in a boiling methanolic alkali gave the 3-methyl ethers of 2-and 4-methoxymethylestrogens, respectively. The structural assignments of the isomers were discussed based on nuclear magnetic resonance, infrared and ultraviolet spectra.
Photochemische Reaktionen. 33. Mitteilung. Die Photoisomerisierung von 3-Oxo-Δ<sup>1;4</sup>-Steroiden in Dioxanlösung Strukturaufklärung der Photoisomeren und Bestimmung der Umlagerungs-Sequenzen
The photo-induced formation of ketonic and phenolic isomers from O-acetyl-1-dehydro-testosterone (1a) and from its 4-methyl homologue 1d in dioxane solution has been described earlier [8][9][13]. The present paper summarizes the findings which resulted in the course of further investigations, and which, in part, have been published in preliminary form [11][14] and in recent reviews [12]. This work
Cross-coupling of [<sup>11</sup>C]methyllithium for <sup>11</sup>C-labelled PET tracer synthesis
作者:Hugo Helbert、Ines Farinha Antunes、Gert Luurtsema、Wiktor Szymanski、Ben L. Feringa、Philip H. Elsinga
DOI:10.1039/d0cc05392a
日期:——
variety of tracers for positron emission tomography (PET) is presented. The radiolabelled products were obtained in excellent yields, at rt and after short reaction times (3–5 min) compatible with the half-life of 11C (20.4 min). The automation of the protocol on a synthesis module is investigated, representing an important step towards a fast method for the synthesis of 11C-labelled compounds for PET
Compounds and methods for modulating mesenchymal cell function, for instance smooth muscle and fibroblast proliferation or cytokine expression, and for treating conditions associated with mesenchymal cell function, for instance airway hyperresponsiveness associated with asthma. The compounds also suppress inflammation. The compounds are a class of estratriene derivates, and includes various derivatives of 2-methoxyestradiol comprising a group A, including a substituted aromatic substituent in the 2-, 6- or 17-position.