Regio- and stereoselective synthesis of 1,4-dihydropyridines by way of an intramolecular interaction of a thiocarbonyl or carbonyl with a pyridinium nucleus

Citation
S. Yamada et al., Regio- and stereoselective synthesis of 1,4-dihydropyridines by way of an intramolecular interaction of a thiocarbonyl or carbonyl with a pyridinium nucleus, TETRAHEDRON, 57(43), 2001, pp. 8939-8949
Citations number
44
Categorie Soggetti
Chemistry & Analysis","Organic Chemistry/Polymer Science
Journal title
TETRAHEDRON
ISSN journal
00404020 → ACNP
Volume
57
Issue
43
Year of publication
2001
Pages
8939 - 8949
Database
ISI
SICI code
0040-4020(20011022)57:43<8939:RASSO1>2.0.ZU;2-4
Abstract
Chiral 1,4-dihydropyridines were prepared by the regio- and stereoselective addition of ketene silyl acetals and organometallic reagents to pyridinium salts. In the addition reaction, an intramolecular interaction between the thiocarbonyl or carbonyl with the pyridinium nucleus plays an important ro le in bringing about the selectivities. The absolute configuration of the n ewly produced stereogenic center of the 1,4-dihydropyridines was determined by X-ray analysis and CD Cotton effects after conversion into the appropri ate derivatives. The working model for the stereoselectivity was proposed b ased on the ab initio calculations at the RHF/3-21G* level. (C) 2001 Elsevi er Science Ltd. All rights reserved.