276239-82-8

Upstream product

• 276240-12-1 (2S,2R,6S)-(+)-2-[2-(2-[1,3]-dioxolan-2-yl-ethyl)-6-methyl-3,6-dihydro-2H-pyridin-1-yl]-2-phenylethanol 
• 276239-73-7 (3R,5S,8aR)-5-methyl-3-phenyl-2,3,8,8a-tetrahydro-2H-oxazolo[3,2-a]pyridine 
• 37610-80-3 1,3-dioxolan-2-ylethylmagnesium bromide 
• 917-54-4 methyllithium 
• 276239-81-7 (2S,2R,4S,5R,6S)-(+)-2-{2-[2-[1,3]-dioxolan-2-yl-ethyl]-6-methyl-4,5-epoxy-3,6-dihydro-2H-pyridin-1-yl}-2-phenylethanol 

Relevant 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

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.