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1.
All four isomers of substituted 3-alkylthio-4-hydroxybutenes have been synthesised: both the geometry of the double bond and the relative stereochemistry of the two chiral centres are controlled. 相似文献
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A sample of deoxosarcophine () was converted into sarcophine () by autoxidation. Two reactions are described that will enable the enantiomers of deoxosarcophine to be interrelated. 相似文献
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Hiroyuki Kikuchi Yasumasa Tsukitani Yasuji Yamada Kazuo Iguchi Steven A. Drexler Jon Clardy 《Tetrahedron letters》1982,23(10):1063-1066
The structure and absolute stereochemistry of lemnalol (1), a new ylangene-type sesquiterpenoid isolated from the soft coral Verseveldt, has been established by spectroscopic, chemical, and x-ray crystallographic analyses. 相似文献
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Starting from the coupling reaction of alkyl cuprates with 1-alkynyl-2-propenyl acetates, the title compounds were prepared by short convenient syntheses. 相似文献
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Nobuyasu Enoki Ryoichi Ishida Shiro Urano Takeshi Matsumoto 《Tetrahedron letters》1985,26(14):1731-1734
The structures , , and have been proposed for three new diterpenes from mainly on the basis of spectroscopic evidence. 相似文献
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Arturo San Feliciano Alejandro F. Barrero Jose M.Miguel Del Corral Marina Gordaliza Manuel Medarde 《Tetrahedron》1985,41(4):671-680
Ele ven -clerodane diterpenoids were isolated from the aerial parts of . Their structures were determined by spectroscopic and chemical methods including the transformation of one of them into the known solidagolactone. 相似文献
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Four novel polyoxygenated C28-sterols have been identified from the soft coral (the Gulf of Eilat, the Red Sea): the 22,28-lactol of 24-methylcholest-5-en-3β,22(R),25-triol-28-al (), 24-methylcholest-5-en-3β,22(R),25,28-tetraol() and the corresponding 5,6β-epoxides ( and ). 相似文献
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Toshihiro Hashimoto Motoo Tori Zenei Taira Yoshinori Asakawa 《Tetrahedron letters》1985,26(52):6473-6476
Four novel fusicoccane diterpenoids, fusicoplagins A, B, C, and D, have been isolated from the liverwort subsp. and the structures determined by spectroscopic methods, chemical transformations, and X-ray crystallographic analysis. 相似文献
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1,3,7,9,11,12,14-Heptazapentacene-2,4,8,10 (14,3,9,12)-tetraones (mixed flavins) were prepared by the cyclization of 1,5-dihydro-8-[N-alkyl-N-(5-nitrouracil-6-yl)-amino-5-deazaflavins with Vilsmeier reagent. The mixed flavins oxidized alcohol under neutral condition in sunlight and a remarkable autorecycling was observed. 相似文献
16.
A new tricyclic C12 hydrocarbon, inflatene (1), possessing unexpected ichthyotoxic properties, has been isolated as the major metabolite of the stoloniferan var. . The structure of inflatene was secured by extensive FT-NMR studies with the natural product and several key derivatives. 相似文献
17.
N-Acyl derivatives of ,-acosamine and ,-ristosamine were synthesized with high stereo selectivity utilizing intramolecular Michael addition of γ- and δ-carbomoyloxy-α,β-unsaturated esters. 相似文献
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J Leitich 《Tetrahedron letters》1980,21(32):3025-3028
The relative rates of formation of and [2+2]cycloadducts of benzyne to , - and , -1,5-cyclooctadiene, - and -cyclooctene are discussed and properties of the adducts (e.g., their unusual hydrogenation) are described. 相似文献
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E.L. Ghisalberti P.R. Jefferies T.A. Mori B.W. Skelton A.H. White 《Tetrahedron》1985,41(12):2517-2526
Three diterpene acids, representing a new class of bicyclic diterpenes, have been isolated from F. Muell. (Euphorbiaceae). Spectroscopic and X-ray cryatallographic evidence for their structure is presented. A rationale for their origin modification of the casbane skeleton is given. 相似文献