Catalytic Hydrogenation of Dimethylpyridine Methiodides and Stereochemistry of Hydrogenation Products
Catalytic hydrogenation of six kinds of N-methylpyridinium iodides gave pairs of geometrical isomers in a certain ratio for each methiodide. ortho-Dimethyl derivatives afforded almost exclusively cis isomers, meta derivatives gave cis isomers predominantly, and para derivative produced almost same a...
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| Published in: | Chemical & pharmaceutical bulletin Vol. 18; no. 12; pp. 2499 - 2506 |
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| Main Authors: | , |
| Format: | Journal Article |
| Language: | English |
| Published: |
Tokyo
The Pharmaceutical Society of Japan
1970
Japan Science and Technology Agency |
| Online Access: | Get full text |
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| Summary: | Catalytic hydrogenation of six kinds of N-methylpyridinium iodides gave pairs of geometrical isomers in a certain ratio for each methiodide. ortho-Dimethyl derivatives afforded almost exclusively cis isomers, meta derivatives gave cis isomers predominantly, and para derivative produced almost same amounts of both isomers. N-Methylpiperidines thus produced were quaternized with methyl iodide to N, N-dimethylpiperidinium iodides. The chemical shifts of equatorial and axial N-methyl protons were compared with each other, from which the substituent effects of α methyl groups was deduced. The results from nuclear magnetic resonance study enabled us completely to analyze the configurations and conformations of the hydrogenation products and their quaternary salts. |
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| ISSN: | 0009-2363 1347-5223 |
| DOI: | 10.1248/cpb.18.2499 |