THE REACTION OF DIETHYL AZODICARBOXYLATE WITH DIHYDROGELSEMINE

1955 ◽  
Vol 33 (4) ◽  
pp. 604-609 ◽  
Author(s):  
Thelma Habgood ◽  
Léo Marion

Dihydrogelsemine reacts with diethyl azodicarboxylate yielding a carbinolamine which forms a methyl ether. Both this ether and the carbinolamine base can be oxidized by chromic acid to the same neutral lactam. That there has been no rearrangement of the carbon skeleton during these reactions is shown by reduction of the methyl ether of the carbinolamine with sodium borohydride to dihydrogelsemine and by reduction of the lactam with lithium aluminum hydride to tetrahydrodesoxygelsemine. It is concluded that both dihydrogelsemine and gelsemine contain a methylene group adjacent to N(b), and from the infrared spectrum of the lactam of dihydrogelsemine, N(b) appears to be part of a five-membered ring.

1951 ◽  
Vol 29 (1) ◽  
pp. 37-45 ◽  
Author(s):  
Morris Kates ◽  
Léo Marion

The infrared absorption spectrum of gelsemine indicates the presence of a carbonyl group. Reduction of the alkaloid with lithium aluminum hydride converts the carbonyl not to a secondary alcohol, but to a methylene group, thus indicating that the carbonyl is present in a lactamic grouping. The reduced base shows the properties of a substituted aniline. Since gelsemine has been shown to yield 3-ethylindole on dehydrogenation with selenium and since the N-atom involved in the lactamic group cannot be the strongly basic nitrogen, gelsemine must contain an oxindole grouping. Furthermore, 3-monosubstituted oxindoles are converted by lithium aluminum hydride to 3-substituted indoles, whereas gelsemine under the same conditions gives rise to a dihydroindole. Therefore, the alkaloid must contain a 3, 3-disubstituted oxindole grouping.


1952 ◽  
Vol 30 (10) ◽  
pp. 761-772 ◽  
Author(s):  
K. Wiesner ◽  
D. M. MacDonald ◽  
Z. Valenta ◽  
R. Armstrong

Pithecolobine, C22H46N4O2, has a lactam group, one primary and two secondary amino groups, and a hydroxyl group. Lithium aluminum hydride converts it into a monocyclic saturated compound, desoxypithecolobine, C22H48N4. Hofmann degradation of this compound gives tetramethylputrescine, trimethyl amine, a doubly unsaturated base C16H31N with a terminal methylene group, and a base C16H34N2. Heating with selenium yields a hydrocarbon, C12;H24–26, with a sequence of six or more CH2 groups. A crystalline oxygen-free compound with two nitrogens (m.p.94 °C.) is also obtained, the ultraviolet spectrum of which is almost identical with aminopyridine.


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