Structure Identification: |
Journal of Organic Chemistry, 1968, 33(9):3425-3428. | Anomalous sodium hydride reduction of norcamphor and 5-norbornen-2-one[Reference: WebLink] |
METHODS AND RESULTS:
Norcamphor and 5-norbornen-2-one both gave significant yields of reduction products (methyl ethers) when treated with sodium hydride and methyl iodide in glyme. Thus, Norcamphor (I) gave 2-methoxynorbornane (II, 10% yield), 3-methyl-2-methoxynorbornane (III, 22%), 3-methylNorcamphor (IV, 27%), 3,3-dimethyl-2-methoxynorbornane (V, 1.4%), and 3,3-dimethylNorcamphor (VI, 38%). 5-Norbornen-2-one (VII) gave endo-and exo-2-methoxy-5-norbornene (VIII, 63%) and 3-methyl-2-methoxy-5-norbornene (IX, 32%). With excess ketone in the latter case, 3-methyl-5-norbornen-2-one (X) was also formed.
METHODS AND RESULTS:
It was shown that the carbonyl is the species being reduced and not the O-alkylation products, 2-methoxynorbornene and 2-methoxynorbornadiene. Possible reasons why these ketones are so easily reduced are suggested.
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