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Intramolecular cyclization of 4‐aryl‐1,4‐dihydropyridine acetals
Author(s) -
Hartman George D.,
Phillips Brian T.,
Springer James P.,
Hirshfield Jordan
Publication year - 1987
Publication title -
journal of heterocyclic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.321
H-Index - 59
eISSN - 1943-5193
pISSN - 0022-152X
DOI - 10.1002/jhet.5570240533
Subject(s) - chemistry , iminium , dihydropyridine , aldehyde , electrophile , aryl , intramolecular force , acetal , titanium tetrachloride , combinatorial chemistry , chloride , medicinal chemistry , stereochemistry , organic chemistry , alkyl , ion , catalysis , calcium
The synthesis of 4‐aryl‐1,4‐dihydropyridines possessing a protected aldehyde functionality at the ortho position is described. These compounds undergo iminium ion mediated cyclization when treated with titanium tetrachloride or gaseous hydrogen chloride. Mechanistically, cyclization utilizes attack of C‐3 of the dihydropyridine on the electrophilic species generated from complexation of the acetal. This methodology highlights opportunities for the construction of novel conformationally constrained dihydropyridine analogs.