The regioselective addition of Grignard reagents to the phenoxycarbonyl salts of 3- (trialkylsilyl) pyridines was studied. Most of the 3-(trialkylsilyl) pyridine salts gave a mixture of dihydropyridines on reaction with aliphatic Grignard reagents. However, all reactions using alkyl or aryl Grignard reagents and the 1-phenoxycarbonyl salt of 3-(triisopropylsilyl) pyridine, or 4-chloro-3-(triisopropylsilyl) pyridine, gave exclusively 1, 2-dihydropyridines ...
