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1,3-Di-tert-butylazulene reacted with highly electrophilic trifluoromethanesulfonate of N-containing heterocycles to give 5-(dihydroheteroaryl)azulene derivatives in good yield and treatment of the 5-(dihydroheteroaryl)azulene derivatives with KOH afforded 5-(heteroaryl)azulenes in excellent yield. 相似文献
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Kiyotake Suenaga Tsuyoshi Mutou Takashi Itoh Noboru Takada Masaki Takagi Hideo Kigoshi Kiyoyuki Yamada 《Tetrahedron》2004,60(38):8509-8527
The bioassay-guided fractionation of the cytotoxic constituents of the Japanese sea hare Dollabella auricularia led to the isolation of aurilide (1), a 26-membered cyclodepsipeptide. The gross structure of 1 was established by spectroscopic analysis including 2D NMR techniques. The absolute stereostructure was determined by chiral HPLC analysis of acid hydrolysates of 1 and by the enantioselective synthesis of a degradation product arising from a dihydroxylated fatty acid portion. The enantioselective synthesis of 1 was achieved in 12% overall yield (16 steps) and confirmed the absolute stereostructure of 1. The cytotoxicity of 1 was evaluated using a synthetic sample, which was found to exhibit potent cytotoxicity against HeLa S3 cells with an IC50 of 0.011 μg/mL. Further biological and pharmacological studies of 1 have been carried out by using synthetic 1. 相似文献
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Akiya Karen Noriaki Ikeda Noboru Mataga Fumio Tanaka† 《Photochemistry and photobiology》1983,37(5):495-502
Formation of singlet charge transfer (heteroexcimer) states in the course of the fluorescence quenching of lumiflavin and riboflavin tetrabutyrate by indole and N-methylindole have been directly observed by means of time-resolved absorption spectral measurements using a picosecond laser photolysis method. Similar transient spectra have been observed also in the case of a flavoenzyme, D-amino acid oxidase. 相似文献
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Yukio Shimura Noboru Ikeda 《Journal of polymer science. Part A, Polymer chemistry》1973,11(6):1271-1280
Bis-ε-aminocaproylaminocaproylhexamethylenediamine ( I ) was synthesized as an analog of 6-nylon pentamer diamine, and its incorporation into block copolymers was studied with the use of α,ω-dihydroxyl, α,ω-bisdimethylchlorosilyl, and α,ω-diepoxy polystyrene. In the course of the experiments, the stability and the reactivity of 4,4′-diphenylmethane diisocyanate and tetramethylene diisocyanate in aprotic dipolar solvents were examined by infrared spectroscopy. The only usable solvent, N-methylpyrrolidone, was found still inadequate for the synthesis involving I, diisocyanate, and α,ω-dihydroxyl polystyrene. A block copolymer having M n = 18,000 was obtained by the reaction of I and α,ω-diepoxy polystyrene. All Tg values of the block copolymers were above 90°C, higher than for polystyrenes with corresponding molecular weight. 相似文献
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Noboru Matsumura Atsushi Ito Masaaki Tomura Yasuyuki Okumura Kazuhiko Mizuno 《Journal of heterocyclic chemistry》2004,41(1):99-102
Tetraazathiapentalene derivative 1 reacts with heterocumulenes such as diphenylketene (2) and 2‐pyridylisothiocyanate (5) to give heterocycles 3, 6 and 7 with elimination of methylisothiocyanate. The reactions of thiadiazolopyrimidine derivatives 8a‐b with ethoxycarbonyl isothiocyanate (9) and carbon disulfide (11) gives heterocycles 10 and 12 via thermal decomposition of 1:1 cycloadducts C and D which have a hypervalent sulfur. The mechanistic and reactivity features of these reactions are described. 相似文献