121507-72-0Relevant articles and documents
REGIO- AND STEREOSELECTIVE ADDITION OF NUCLEOPHILES TO 1-PHENOXYCARBONYL-2,3-DIHYDROPYRIDINIUM SALTS
Comins, Daniel L.,Chung, Geewon,Foley, Michael, A.
, p. 1121 - 1140 (2007/10/02)
Several 2-alkyl-1-phenoxycarbonyl-Δ3-piperidines were prepared by the addition of alkylzinc iodides to dihydropyridinium salt (9).The treatment of 4-hydroxy-2-methyl-1-phenoxycarbonyl-1,2,3,4-tetrahydropyridine (12) with allyltrimethylsilane in the presence of a variety of Lewis acids was studied and found to give cis- and trans-2,6-dialkyl-Δ3-piperidines (14) and (15) in moderate to good yield.Among the Lewis acids studied, stannyl chloride gave the best yield with good stereoselectivity (84:16) favoring the cis-isomer (14).The analogous reaction of the 4-metho xy derivative (13) with organozinc reagents was examined and found to give the cis-isomers (17) as the major products.Using this metodology, the cis-piperidine alkaloid (+/-)-dihydropinidine, was prepared in six steps from 4-methoxypyridine.
THE ADDITION OF ALKYLZINC IODIDES TO 1-(PHENOXYCARBONYL)-2,3-DIHYDROPYRIDINIUM SALTS. A SYNTHESIS OF 2-ALKYL-Δ3-PIPERIDINES.
Comins, Daniel L.,Foley, Michael A.
, p. 6711 - 6714 (2007/10/02)
Several 2-alkyl-1-(phenoxycarbonyl)-Δ3-piperidines were prepared by the addition of alkylzinc iodides to 1-(phenoxycarbonyl)-2,3-dihydropyridinium salts.