SYNTHESIS OF 3,5-DIACYL-4-PHENYL-1,4-DIHYDROPYRIDINES

3,5-Diacyl-4-phenyl-1,4-dihydropyridines have been synthesized via a r egio- and chemoselective addition of Ph2Cu(CN)Li-2 to beta-substituted N-alkylpyridinium salts, followed by acylation of the intermediate 1, 4-dihydropyridines with trichloroacetic anhydride and subsequent halof orm-type reaction. A similar sequence using an N-silylpyridinium salt and PhMgBr allows the preparation of the corresponding N-unsubstituted dihydropyridines. (C) 1998 Elsevier Science Ltd. All rights reserved.