276240-13-2Relevant academic research and scientific papers
Stereocontrolled alkylation of chiral pyridinium salt toward a short enantioselective access to 2-alkyl- and 2,6-dialkyl-1,2,5,6- tetrahydropyridines
Guilloteau-Bertin, Berangere,Compere, Delphine,Gil, Laurent,Marazano, Christian,Das, Bhupesh C.
, p. 1391 - 1399 (2007/10/03)
Treatment of salts 1a-b with Grignard reagents gives, after reduction of the resulting unstable dihydropyridines 7, the tetrahydropyridines 8a-c, with modest selectivities but in very few steps and under practical conditions. Higher stereo and regioselectivities are obtained with salt 1c which gives the tetrahydropyridines 15a-e. In addition, the dihydropyridine intermediates 11b cyclize to give the new oxazolidine derivatives 12a-e, which turn out to be good precursors of the 2,6-trans-disubstituted tetrahydropyridines 21a-e. Selective syntheses of (-)-lupetidin, (+)-solenopsin, and indolizidines (-)-5 and (-)-6 are presented as representative examples of applications.
