[Intramolecular alkylation of aromatic compounds. 35. Di- and  tetrahydropyridinemethylindolines as potential precursors of  ergolines]  .
In the presence of methyl chloroformate, compound 6a is reduced by NaCNBH3 yielding the 1,6-dihydropyridine derivative 7. Under the same conditions the indoline 10 accessible from 6a via 9a gives a mixture of the 1,4- and 1,6-dihydropyridine derivatives 11 and 12. As by-product of the reduction the borane adduct 13 is detected. In contrast the methoiodide 1 is reduced by NaBH4 or DIBAH giving a separable mixture of the diastereomers of the tetrahydropyridines 2 and 3; on catalytic hydrogenation the piperidine derivative 4 is formed. Cleavage of the enolether moiety in 3a and 7 provides the corresponding piperidones 5 and 14, respectively. Using prolonged reaction time 7 is hydrolized quantitatively furnishing the 1,4-diketone 15.
Reimann
E
E
Department of für Pharmazie, Zentrum für Pharmaforschung, Ludwig-Maximilians-Universität München, Germany. ebrei@cup.uni-muenchen.de
Erdle
W
W
D000478:Alkylation; D004873:Ergolines / Q000138:chemical synthesis*; D007202:Indicators and Reagents; D007211:Indoles / Q000138:chemical synthesis*; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D011725:Pyridines / Q000138:chemical synthesis*; D013055:Spectrophotometry, Infrared
D004873:Ergolines; D007202:Indicators and Reagents; D007211:Indoles; D011725:Pyridines
Intramolekulare Aromatenalkylierungen. 35. Mitt.: Di- und Tetrahydropyridinylmethylindoline als potenzielle Vorstufen zu Ergolinen.