B. Trofimov, A. Mal’kina, V. V. Nosyreva
Feb 22, 2012
Citations
0
Influential Citations
8
Citations
Journal
Tetrahedron Letters
Abstract
Abstract Ethyl isonicotinate reacts with tertiary cyanoacetylenic alcohols under exceptionally mild conditions (room temperature, without catalyst or solvent) to afford novel polycondensed heterocyclic systems, 4,15-dioxa-7,12-diazapentacyclo[9.5.2.02,10.03,7.012,16]octadeca-8,17-dienes, in 30–68% yields. This tandem cyclization is regio- and stereospecific. Despite several asymmetric carbons (up to six) being present in the molecules, only one diastereomer is formed and both cyanomethylidene fragments possess exclusively Z-configuration. The tandem sequence includes the formation of 1,3-oxazolidino-1,2-dihydropyridines which undergo Diels–Alder cyclodimerization to give the final products.