置換ピリジニウム塩類のNaBH₄による還元 (第4報)

1-Methyl-2-methoxycarbonylpyridinium IodideのNaBH₄による還元

抄録

The reduction of 1-methyl-2-methoxycarbonylpyridinium iodide by NaBH₄ in methanol gave 1-methyl-2-methoxycarbonyl-1, 2, 3, 6-tetrahydropyridine and 1-methyl-2-methoxy-carbonyl-1, 6-dihydropyridine and the reduction in sodium hydroxide alkali methanol gave only 1, 6-dihydro compound. The reduction of 2-methoxycarbonyl derivative (I) by NaBH₄ gave, different from the case of the 3- or 4-substitute, 1, 6-dihydro compound firstly, reduced only from Ib structure, a part of which will be further reduced to 1, 2, 3, 6-tetrahydro compound.
The structure of tetrahydro compound has been determined by the NMR measurement of its methyl iodide salt in heavy water and that of dihydro compound by the IR spectrum analysis.