78584-61-9Relevant academic research and scientific papers
A Novel Synthesis of 2-Aryl-4-Piperidones By Mannich Cyclization of Iminoketals (1)
Bosch, Joan,Rubiralta, Mario,Moral, Montserrat,Valls, Maria
, p. 595 - 606 (2007/10/02)
2-Aryl-4-piperidones have been synthesized by condensation between an aromatic aldehyde and a β-aminoketone ethylene ketal, and further cyclization of the resulting iminoketal with dry hydrogen chloride or anhydrous p-toluenesulfonic acid.Alternatively, r
Reinvestigation of the Stevens Rearrangement of 1-Benzyl-1,3,4-trimethyl-1,2,5,6-tetrahydropyridinium Salts II. Synthesis of 2-Aryl-3-isopropenyl-1,3-dimethylpyrrolidines
Bosh, Joan,Rubiralta, Mario
, p. 485 - 494 (2007/10/02)
cis-2-Aryl-3-isopropenyl-1,3-dimethylpyrrolidines IIa and IIb have been synthesized by an unambiguous way, thus confirming the structure of the methylene derivatives obtained as by-products in the Stevens rearrangement of 1-benzyl-1,3,4-trimethyl-1,2,5,6-tetrahydropyridinium salts Ia and Ib.The synthesis is based on the acid-induced intramolecular cyclization between an iminium salt and the α-position of a ketal group.Thus, condensation between amino ketal XXI, prepared via Gabriel synthesis from 5-chloro-3-methyl-2-pentanone, and the appropriate aldehyde afforded imines XXI.Their treatment with dry hydrogen chloride followed by acid hydrolysis and methylation gave 3-acetylpyrrolidines IV, which were transformed into the isopropenyl derivatives II by reaction with methyl-lithium and further dehydration.
