Contact glow discharge electrolysis (CGDE) is a type of chemical reaction carried out by means of an electric discharge between an aqueous solution containing various substrates and an electrode in contact with the solution. The primary products of the aqueous solution are hydroxyl and hydrogen radicals which react with the substrates to form substrate radicals. These radicals react with each other to form various secondary products. Dehydrogenation, oxidation, amination, carboxylation and degradation reactions of bioorganic compounds by using CGDE were carried out. The oxidation by CGDE is an extremely strong and clean oxidation process without using any oxidizing agent. The reactions by CGDE are relatively controlled reactions compared with the gas phase discharge reactions. This new type of chemical reaction by CGDE might be applicable to the reactions which could not be carried out in conventional ways.
This review describes the new aspects of liposome. Liposome has three different types- (1) multilamellar vesicle (MLV), (2) small unilamellar vesicle (SUV), (3) large unilamellar vesicle (LUV) is the best mimetic model for a cell. Each type has its own preparation method, which is discussed in this review. More stable liposome has been investigated. The lipid derivatives containing the polymerizable groups are synthesized and the liposome prepared with these compounds are photochemically polymerized. The structure of liposome remains unchanged during polymerization. Polymerization of liposome increases the stability.
Various new methods for the synthesis of 4-substituted indoles were developed. These involved a) three step synthesis of N-methyl-1, 3, 4, 5-tetrahydropyrrolo [4, 3, 2-de] isoquinolines, b) one step synthesis of 4-methylaminomethylindole, c) one pot sythesis of 4-hydroxymethylindole, d) the synthesis via 4-indolediazonium salts. Short step synthesis of ergot alkaloids, (±) -6, 7-secoagroclavine, was also achieved by 5 routes, utilizing such novel reactions as a) selective mono-alkylation of nitroalkanes with gramines, b) γ-alkylation of allyl alcohol with nitroalkanes, and c) reductive alkylation of nitroalkanes with Grignard reagents.
Mugineic acid (1), an amino acid isolated from the roots of water-cultured barley (Hordeum vulgare L. var. Minorimugi), is the first phytosiderophore to be shown to play a role in the uptake and transport of iron in higher plants. The structure of 1 was determined as 2 (S), 2' (S), 3' (S), -3'' (S) -N- [3-carboxy-3- (3-carboxy-3-hydroxypropylamino) -2-hydroxypropy1] -2-azetidine-2-carboxylic acid by a direct X-ray crystallographic method, and chemical and physico-chemical studies of the degradated products of 1. Structures of other analogous amino acids from some graminaceous plants were also elucidated. Stereospecific total syntheses of 2'-deoxymugineic acid (9) and avenic acid A (11) were achieved by using common key intermediate 28 obtained from L-α-hydroxy-γ-butyrolactone (17) in short steps. N-Alkylation procedure by means of sodium cyanoborohydride in neutral media were effective for condensation of optically active units (e. g. 16c+24 25). The N, O-protecting groups were removed in two steps at the final stage of the synthesis. The structures and properties of metal complexes of mugineic acid were examined by X-ray crystallographic analysis, the potentiometric titration, spectroscopic, and electrochemical studies.
Stereoselectivities in the nucleophilic addition of various nucleophiles to various 2-, 3-, 4-uloses were examined, and discussions were made on the possible, conformational change of substrates and on the following, three, main factors to control the stereoselectivities depending on the nature of reactions ; a) non-bonded interactions, after the preceding, conformational change by the coordination of magnesium to the C=O and adjacent C-O oxygens (methylmagnesium iodide) or by the solvent-dependent, dipole repulsion between the C=O and C-O bonds (methyllithium), b) intramolecular, electrostatic, attractive force between an axial oxygen or lone-paired electron of ringoxygen and diazomethyl cation in the transition states (diazomethane), c) thermodynamical stabilities of epimers to be produced in equilibration reaction.
Conjugated nitroolefins were found to react with silyl enol ethers, ketene silyl acetals, and 2-monoalkyl-and 2-unsubstituted 1, 3-dicarbonyl compounds to give 1, 4-diones, γ-ketoesters, triones, and furans, respectively. 1-Nitro-1-phenylthiopropene, a new nitroolefin, was synthesized and has been developed as the reagent for 3-methylfuran synthesis. Some of these reactions have also been applied to the total synthesis of gymnomitrol, curzerenone, epicurzerenone, evodone, ligularone, and isoligularone.
The reaction of γ-thiobutyrolactone (A) with hydrazine hydrate gave N, N'-bis (4-mercaptobutane) hydrazide (1) in 70 % yield. Similarly, the reaction with phenylhydrazine, aminoguanidine and semicarbazide gave hydrazide (2), triazole (3) and azine (4) derivatives, respectively. Furthermore, it was found that the reaction of A with thiosemicarbazide afforded medium ring compound (5) and thiadiazole derivative (6).