Orthophosphoric acid has been found to accomplish the previously unsuccessful oyclization of azomethines of 3-formylcarbazoles and aminoacetal to substituted pyrido[4,3-b]carbazoles according to a scheme proposed by Cranwell and Sexton. By this method, there have been prepared 6,ll-dimethyl-(ellipticine), 5,6,11trimethyl-, 5,9,11-trimethyl-, 9-methoxy-5,ll-dimethyl-(9-methoxyellipticine), 9-methoxy-5,6,11-trimethyl-, 9-bromo-6,ll-dimethyl-, and 9-nitro-5,ll-dimethyl-6H-pyrido[4,3-blcarbazole.
Cyclodehydration in
orthophosphoric acid of the azomethines of 3- formyl-carbazoles and
aminoacetals has yielded 5-methyl- (IId), 3,5,11-
trimethyl-(11b), 3,5,9,11-tetramethyl-(IIc), and
5,7,10,11-tetramethyl- 6H-pyrido[4,3-b]carbazoles (IIa).
In the same way γ-carboline and 6,9- dimethyl-γ-carboline were
obtained from the azomethines of 3-formyl- and 3-formyl-4,7-dimethyl-indole. A Doebner reaction with 3-amino-2- methylcarbazole, acetaldehyde,
and pyruvic acid yielded 1-carboxy-3,5- dimethyl-7H-pyrido[2,3-c]carbazole (VIIIb) from which was derived the methyl ester (VIIIc) and 3,5-dimethyl-7H-pyrido [2,3-c]carbazole (VIIIa).
Tigaso oil, which is obtained as an
exudate from a tree of the Anacardiaceae family identified as Campnosperma sp.
vel. aff. C. brevipetiolata Volk., has been found to contain an optically
active compound. This is considered to be (+)-5-hydroxy-5-(nonadec- 10'-en-2'-onyl)cyclohex-2-enone
(V), a new type of natural product. It is very closely related to the phenol,
campnospermonol (I ; R=H) which is the major component of Tigaso oil, and is
readily converted into a mixture of campnospermonol and campnospermonyl alkyl
ether by heating in alcoholic hydrochloric acid. On pyrolysis, V yields
resorcinol and methyl oleyl ketone almost quantitatively.
($)-3-Hydroxy-3-(nonadecan-2'-ony1)cyclohexanone
(VI) obtained by catalytic hydrogenation of V is easily dehydrated to
3-(nonadecan-2'-onyl)cyclohex-2-enone (VII) which has acidic properties and
gives a yellow solution in alkali. Heating VII in alkali gives stearic acid and
3-methylcyclohex-2-enone as the principal products. When the hydroxydiketone
(VI) is heated the major reaction is dehydration to give VII, but pyrolysis
also takes place, giving methyl stearyl ketone and dihydroresorcinol.
3-(Nonadecan-2'-ony1)cyclohexanone (VIII) is obtained by catalytic
hydrogenation of VII and also by oxidation of the diol X, itself prepared from
hydrocampnospermonol (II ; R =H) by high pressure hydrogenation.
The structure originally assigned to
campnospermonol by Jones has been established by the synthesis of
hydrocampnospermonyl methyl ether, from 3-methoxyphenylacetyl chloride and
diheptadecyl cadmium.
The odour of Tigaso oil is partly due to a
small amount of a volatile ketone C7H12O which consists
mainly of 3-methylcyclohexanone ; probably a mixture of (+)- and (-)-isomers
with the (-)-isomer preponderant.
Ethyl sodiomalonate
with fluorene-9-spiro-2'-oxiran gave two carboxybutyro-lactones,
(2a) and (3a). Fluorene-9-spiro-4'-(2'-methylenebutyrolactone) (3c) and
2-methylene-4,4-diphenylbutyrolactone (6c) have been prepared by the action of diethylamine and formaldehyde on their respective
2-oarboxybutyrolaotones. The reaction of trimethylsulphonium
iodide with 4,4'-diethoxybenzophenone gave 2,2-bis(4'-ethoxypheny1)vinyl
alcohol (6a) and not the oxiran.
The Mannich
reaction of a dialkylamine and formaldehyde with 2-carboxy-
butyrolactones leads directly to isolable
2-methylenebutyrolactones. It is suggested that this happens through a
concerted decarboxylation-elimination mechanism. 2-Methylene-3- and -4-phenylbutyrolactones
and their cysteine addition products, and
3-methylene-2-oxo-cis-2,3,3a,4,5,9b-hexhydronaphtho[1,2-b]furan
and its di-methylamine addition product have been
prepared. 3-Oxo-2,3,4,4a,6,6-hexahydro-naphtho[l,2-c]pyridazine has also been
synthesized.
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