A new stereoisomer of methyl santoninate was synthesized and by the examination of the behavior of this substance as well as its C₈-epimer toward alkali, the axial Position was assigned to the C₇-C₁1 bond of santonin A. A novel route for the preparation of a cross-conjugated dienone is also described.

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Configurational assignment has been made for three isomeric compounds obtained by the performic acid-oxidation of the enol acetate (II). The major product, which became an important intermediate for the total synthesis of santonin, has been given the structure of ethyl 11-ethoxycarbonyl-6α-hydroxy-3-oxo-11-epi-eusanton-4-enic acid lactone (III), and the other two were proved to be the C₁₁-and the C₆-epimer of (III). The mechanism of the oxidation reaction is also discussed briefly.

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(-)-α-Santonin has been correlated stereochemically with (+)-11-carboxy-3-oxoeusanton-4-enic acid (X) and by the investigation of molecular rotation of the latter the absolute configuration of the former has been deduced. It has been shown that(-)-α-santonin belongs to the same stereochemical type as steroids.(-)-β-Santonin proved to be the C₁1-epimer of (-)-α-santonin.

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New optically active stereoisomers of santonin were synthesized and their absolute configurations investigated. It has been shown that(-)-6α-hydroxy-3-oxo-11-epi-isoeusatona-1, 4-dienic acid lactone, (-)-6β-hydroxy-3-oxoeusantona-1, 4-dienic acid lactone, and (-)-6β-hydroxy-3-oxo-11-epi-eusantona-1, 4-dienic acid lactone are of the same stereochemical type as that of the naturally occurring santonins. An aspect of the mechanism of the dienone-phenol rearrangement in santonin series was also considered.

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Starting from 3-oxo-11-epi-eusantona-4, 6-dienic acid (IV ; R=H) and 3-oxoeu-santona-4, 6-dienic acid (VIII ; R=H), α-(5, 6-dihydroxy-4, 9-dimethyl-3-oxo-3, 5, 6, 7, 8, 9-hexahydronaphthyl-6)propionic acid lactones-A and -B (Xa and Xb) were synthesized, which would probably be racemic stereoisomers of artemisin.

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Reduction of 4-nitro-2, 6-lutidine 1-oxide (Ia) and 4-nitro-3-picoline 1-oxide (Ib) under various conditions was examined. Upon catalytic reduction with palladium-charcoal in aqueous solution, (Ia) and (Ib) were respectively reduced to 4-amino-2, 6-lutidine 1-oxide (IIa) and 4-amino-3-picoline 1-oxide (IIb). However, in methanolic solution or 10% hydrochloric acid solution, the reduction did not proceed smoothly and azo derivatives (Va, Vb) were obtained as a by-product. In glacial acetic acid, to which a small amount of acetic anhydride had been added, the reduction proceeded smoothly and 4-amino derivatives (IIIa, IIIb) were obtained. By the reduction of (Ia) and (Ib) with hydrogen sulfide or sodium nitrite, 4, 4'-azo-2, 6-lutidine 1, 1'-dioxide (Va) and 4, 4'-azo-3-picoline 1, 11'-dioxide (Vb) were obtained. When zinc dust was used as a reducing agent 4, 4'-azoxy 1, 1'-dioxide compounds(IVa, IVb)were obtained.

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The Skraup reaction of 4-aminomethylpyridine 1-oxides, which were easily prepared from the 4-nitro 1-oxides, afforded 1, 6-narhthyridine derivatives ; 5, 7-dimethyl-1, 6-naphthyridine 6-oxide (II) from 4-amino-2, 6-lutidine 1-oxide (I), 8-methyl-1, 6-naphthyridine 6-oxide (IV) from 4-amino-3-picoline 1-oxide (III), 7(5?)-methyl-1, 6-naphthyridine 6-oxide (VI, VII?) from 4 -amino-2-picoline 1-oxide (V), and 1, 6-naphthyridine 6-oxide (IX) from 4-aminopyridine 1-oxide (VIII), but the yield of these compounds was all poor.

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Alkylbenzenes were condensed with propionic anhydride in the presence of aluminum chloride into p-alkyl propiophenones, which were converted into p-alkyl-α-isonitrosopropiophenones by treatment with butyl nitrite. These isonitrosoketones were first reduced into aminoketones in dehyd. ethanol containing hydrogen chloride in the presence of palladium-carbon catalyst, and the p-alkyl-α-aminopropiophenone hydrochlorides were converted into amino alcohols in water by the aid of the same kind of catalyst. α-(p-Alkylphenyl)-β-aminopropanols, or p-alkyl-norephedrines, thereby obtained are probably a mixture of compounds of regular and pseudo forms. In order to obtain each of them separately from the mixture, the elaborate method of Taguchi et al. was applied in a modified form. By these mothods, p-methyl-, p-ethyl-, p-propyl-, p-butyl-, p-amyl-, p-hexyl-, p-heptyl-, p-otyl-, p-decyl-, and p-dodecyl-ephedrines and the corresponding norephedrines were obtained. In addition, these ring-substituted ephedrines and norephedrines were divided into the regular- and pseudo-series.

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3-Hydroxy-N-methyl-4b, 8a-methanoiminomethano-4b, 5, 6, 7, 8, 8a, 9, 10-octahydro-phenanthrene, a compound in which the morphan skeleton in 3-hydroxy-N-methyl-morphinan had been substituted with a hexahydroisoindoline ring, was synthesized and its analgesic action was tested.

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The infrared spectra of eight ethylpyridines and nineteen methylpyridines were determined. The absorption spectra obtained are correlated with their structures and are discussed on the characteristic properties of the pyridine ring and its similarity to the benzene ring. The conclusion are as follows : (i) Out-of-plane C-H deformation frequencies in alkylpyridines are determined principally by the number of adjacent free hydrogen atoms round the ring in a similar way to substituted benzenes, (ii) furthermore, their exact frequencies have a distinct correlation with the arrangement of hydrogen atoms round the ring, (iii) ethylpyridines always absorb at higher frequencies than those of the corresponding methyl homologs, and (iv) pyridine ring vibrations between 1450 and 1650 cm^-1 are also regularly correlated to the structures.

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The infrared and ultraviolet absorption spectra of several mono- and bicyclic α-bromo-, α, β-, and α, β : α'β'-conjugated ketones were investigated. The conformation of bromine atom in α-bromoketones was discussed mainly on the basis of the spectral data. The conclusion obtained for these compounds was in good agreement with that of α-bromoketosteroids. It was especially found that the foregoing argument about secondary α-bromo ketones applied well to tertiary α-bromo compounds.

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5-Hydroxytetralone-(1) gave a green fluorescence when heated in sulfuric acid with hexoses, oligosaccharides, or polysaccharides which contains hexose units in their molecule. The reaction was sensitive and specific for hexose, and interfered by only a few substances. The limit of the detection of hexoses, oligosaccharides, and polysaccharides was tabulated, and a new syntheses of the reagent was described.

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Alkyl- or benzylpyridylcarbinols (α or γ) were obtained from alkyl or benzyl (α or γ) picolyl ethers by the application of sodium amide in Decalin, xylene, or benzene. This indicates that the sodium amide forms a carbanion by the polar effect of nitrogen and the carbanion electron attacks the carbon with a low electron density in the rearranging radical, thus the rearrangement takes place. Ethyl, benzyl, secbutyl (α or γ)-picolyl ethers underwent the rearrangement to carbinols, but rearrangement product could not be isolated from ethyl β-picolyl ether, in which the effect of nitrogen is small, and from phenyl (α or γ) picolyl ethers, in which a carbon with a low electron density is not formed. In benzyl picolyl ethers, the carbanion is formed from the carbon directly bonded to the pyridine ring, and benzyl-(α or γ)-pyridylcarbinol is obtained by the rearrangement reaction.

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The Synthesis of thiazolo[5, 4-c]pyridines was accomplished by the Curtius degradation of 3-mercaptoisonicotinic acid hydrazide and cyclization of the resulting 4-aminopyridine-3-thiol with formic acid or acetic anhydride.

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The ultraviolet absorption spectra of thiazolopyridine and its substitution products, and of benzothiazole were comparatively studied.

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Paper chromatography of essential oils succeeded by the use of paraffine- and cetaceum-coated papers. Aromatic essential oils were well separated.

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