3- (Pentadeca-8', 11', -dienyl) veratrole and 3- (pentadeca-8', 11', 13'-trienyl) veratrole, diolefinic and triolefinic components of Urushiol dimethyl ether, were synthesized. 8- (2, 3-Dimethoxyphenyl) octanal was prepared by the reaction of octan-1, 8-dial monoacetal with 3-veratryl lithium, followed by dehydration, hydrolysis, and hydrogenation. Wittig's reaction of 8- (2, 3-dimethoxyphenyl) octanal and butanal with trimethylene bis-triphenylphosphonium bromide gave 3- (pentadeca-8', 11'-dienyl) veratrole. Similarly, 3- (pentadeca-8', 11', 13'-trienyl) -veratrole was prepared from 8- (2, 3-dimethoxyphenyl) octanal, crotonaldehyde and the bis phosphonium salt.
The mass spectra of several alcohol esters (C1C5) of lauric acid were studied in order to investigate the influence of the ionization voltage on the length and iso-structure of alcohol chain. Generally, hydrocarbon peaks at 20eV and 30eV were smaller than the corresponding ions at 70eV in the mass spectra of these laurates. However, following peaks showed especially larger relative intensity at 20eV and 30eV than that at 70eV, at m/e 201 in propyl, butyl and n-amyl esters, at m/e 60 and 200 in iso-propyl laurate. In the mass spectra of propyl, butyl, and amyl esters, a rearranged ion peak_??_was observed at m/e 201. The peak at m/e 183 due to_??_was found in all laurates. These two peaks are characteristic of laurates and useful for the identification of laurates. The correlation of the mass spectra of the laurates with the length and iso-structure of alcohol chain was discussed, and fragments of alcohol groups of iso-structure were much higher than those of normal structure.
Procedures for the rapid determination of BHT, BHA, Dowtherm and Neo-SK-oil in fatty oil were presented by authors. Fatty oils containing antioxidants or heat transfer medium are directly injected into precolumn which is attached to gas chromatograph to protect the main column from contamination with the unvolatiles. Each analysis takes only 20min. at maximum. Gas chromatograph-mass spectroscopy system was found useful for the final identification of the antioxidant peaks. Investigation of the change of BHT and BHA contents in heated oils by the precolumn method showed the monotonical decrease of the contents under the effective stirring at 180210°C.
In the previous paper of this series, the retention characteristics of 4-methyl sterols were investigated with a view for establishing a systematic relationship between the structure of sterols and their gas chromatographic characteristics. The present report deals an extended study on 6-methyl sterols prepared from cholesterol. The retention data for five 6-methyl sterols and for their derivatives at C-3 were expressed in terms of relative retention times (Table-1), methylene unit values (Table-2) and retention factors due to the introduction of 6-methyl group into sterols (Table-3), on SE-30, OV-17 and DEGS phase, respectively. Main results obtained were as follows : 1) The retention times of 6-methyl sterols and their derivatives were generally or mostly found to be larger than those of the corresponding non-methylated sterols and their derivatives. However, 6-methylcholesteryl-trifluoroacetate exhibited a retention time smaller than that of cholesteryl-trifluoroacetate on OV-17 phase. On DEGS phase, the trimethyl-silylether derivatives of 6 α-methylcholestanol and 6-methylcholesterol exhibited almost same retention times as compared with the corresponding non-methylated derivative. 2) The effect of intramolecular interaction between 6-methyl group and a C-3 functional group on the retention time was less marked as compared to the case with 4-methyl group (Fig-1). 3) The saturated compound with 6 α-methyl group was eluted faster than the corresponding 6 β-methyl isomer. On the other hand, the reverse was the case with 6 α-methyl-Δ4-cholesten-3-one and 6 β methyl Δ4 cholesten-3-one, and the latter eluded before the former.
The reaction of methyl linoleate and methyl acrylate in the presence of the conjugation catalyst such as nickel-on-carbon, palladium-on-carbon, chromium hexacarbonyl, methyl benzoate-chromium tricarbonyl, iron pentacarbonyl, anthraquinone, activated aluminium oxide and potassium tert.-butoxide was studied. Among the catalysts employed in this study, iron pentacarbonyl was found to be the most effective. The 1 : 1 Diels-Alder adduct from methyl linoleate and methyl acrylate was obtained in 76% yield by heating a mixture of methyl linoleate, methyl acrylate (1.5 moles per mole of methyl linoleate) and iron pentacarbonyl (5mol% of methyl linoleate) for 17hr at 230°C under nitrogen pressure of about 5kg/cm2. The yield of 1 : 1 adduct increased to 88% when about 5kg/cm2 of carbon monoxide was used instead of nitrogen. Besides the 1 : 1 adduct as the main product, 1 : 2 adduct, 1 : 3 adduct, and copolymer of methyl linoleate and methyl acrylate were also formed.
For establishment of the standard method of carbonyl value analysis of fats and oils, collaborative studies were made on the method of Henick et al., stressing onto the agreement and reproducibility among data. Good result was obtained by fixing the time for 5 minutes, which is defined as the elapsing time from addition of 4%-KOH-ethanol solution up to the time of dilution with ethanol. The effect of peroxides on carbonyl value determination was also investigated for the stannous chloride reducing method of Mizuno et al.. The results indicated that carbonyl value was measured excessively when peroxides are present. Therefore, carbonyl value should be measured after removing the effect of peroxides. Calculation of carbonyl value : CO.V.=A/B A; absorbance at 440mμ B; sample weight in 5ml of sample-benzene solution (g)
A method for the quantitative determination of surfactants containing NH groups in molecules was examined by thin layer chromatography. Surfactants containing NH groups such as long chain N-acylglutamates were chromatographed by a silicagel-coated plate and could be easily detected by N-chlorination and subsequent spraying with starch-potassium iodide solution. A minimum amount for detection was about 0.5μg. The color intensity was proportional to the concentration of a sample spotted, and therefore, the amount of the surfactant could be determined by comparison with the standard solution on the color intensity.