Search results for "Wagner–Meerwein rearrangement"
showing 2 items of 2 documents
Proton Acid-Catalysed Transformations of Estrogen Derivatives: New Results and Some Mechanistic Aspects of theKober Colour Reaction
1994
The 3-O-methylated estrogen derivatives 1a-d and α-estradiol (1e) underwent sulfuric acid-catalysed transformations to furnish the steroids 2–6. The processes involved in the reaction sequence are regioselective sulfonation and, above all, the Wagner-Meerwein rearrangement of the methyl group at C-13. With the objective of obtaining further information on the course of the Kober colour reaction of estrogens, some UV/VIS and ESR spectroscopic investigations were also carried out. Protonenkatalysierte Transformationen von Estrogen-Derivaten: Neue Ergebnisse und einige mechanistische Aspekte der Kober-Farbreaktion Die O-methylierten Estrogenderivate 1a-d und α-Estradiol (1e) reagieren in Schwe…
First Electrophilic Substitutions of 3-Substituted Indoles with Diethoxycarbenium Tetrafluoroborate: Functionalized Indole Derivatives
1990
The indoles 2a-2c react with diethoxycarbenium tetrafluoroborate (1) to furnish the indolecarbaldehydes 3a-3d. In the thermodynamically controlled reaction of 3-methylindole (2a) with 1 the tris(indolyl)methane 4 and diskatole (5), are formed in addition. The limitations of these reactions are discussed and evidence is presented for a C-3-ipso-attack and a Wagner-Meerwein rearrangement, respectively, leading to the formation of 3b or 3d. Erste elektrophile Substitution von 3-substituierten Indolen mit Diethoxycarbenium-Tetrafluoroborat: Funktionalisierte Indol-Derivate Die Indole 2a-2c reagieren mit dem per se synthetisierten Diethoxycarbenium-Tetrafluoroborat (1) zu den Indolcarbaldehyden …