• Title/Summary/Keyword: Diels-Alder adduct

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Synthesis of a Conformationally-rigid Etorphine Analogous

  • Kim, Keun-Jae;Hahn, Soon-Jong;Lyu, Hark-Soo
    • Bulletin of the Korean Chemical Society
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    • v.7 no.3
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    • pp.166-169
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    • 1986
  • In order to synthesize conformationally rigid etorphine analogues having potentially interesting pharmacological activities, synthesis of compound 3 by the reaction of compound 4 and compound 5 via intramolecular Diels-Alder reaction has been attempted. However, the reaction did not go well and the compound 3 would not be isolated. Therefore, intermolecular Diels-Alder reaction using dimethyl acetylene dicarboxylate was attempted. As shown in scheme 2, Diels-Alder adduct 9 was converted into the target molecule 14 containing the new [2.2.2] bicyclo octane ring in good yields.

Synthesis of new Thebaine Derivatives with Phenylsulfonylpropadiene

  • Kim, Keun-Jae;Lee, Jung-Sei
    • Bulletin of the Korean Chemical Society
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    • v.10 no.2
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    • pp.129-132
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    • 1989
  • Reactions of thebaine with phenylsulfonylpropadiene in various solvents were investigated. It was found that Diels-Alder reaction adduct was obtained in nonpolar solvent, while addition reaction adduct was obtained in polar solvent. Transformations of these two products were also carried out.

Elucidation of Selectivity Difference in the Diels-Alder Reactions of 6,6-Disubstituted Cyclohexa-2,4-dienone

  • Jeong, Jun-Pyeong;Lee, Oh-Seuk;Yang, Ki-Yull
    • Bulletin of the Korean Chemical Society
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    • v.23 no.6
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    • pp.829-837
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    • 2002
  • Recently it was reported that cycloaddition of 6,6-disubstituted cyclohexa-2,4-dienone, 1 with cyclopentadiene gave solely the adduct of type 1.while its reaction with 1,3-cyclohexadiene gave both Ⅱ and Ⅲ. Semiempirical MO calculations were done to elucidate the origin of the selectivity difference between the two dienes. Cycloaddition of 1 with cyclopentadiene is controlled thermodynamically to give only 1-diene adduct by ΔGvalues of 10.6-20.3 kcal/mol, while its reaction with 1,3-cyclohexadiene does not show 1-diene/1-dienophile selectivity due to similar stabilities of the two adducts. Thermodynamic parameters also show that 두애 adducts are more fabourably fromed in the cycloadditions of 1 with both cyclopentadiene and 1,3-cyclohexadiene, which coincides with experimental observations. Cope rearrangements of endo adducts are another avenue to convert between 1-diene and 1-dienophile.

Asymmetric Intramolecular Diels-Alder Cycloadditions of 2-Pyrone-3-Carboxylates and Synthesis of Vitamin $D_3$ A Ring Phosphine Oxide

  • 조천규;Gary H. Posner
    • Bulletin of the Korean Chemical Society
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    • v.19 no.9
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    • pp.957-961
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    • 1998
  • Intramolecular Diels-Alder cycloadditions of 2-pyrone-3-carboxylates with trans-vinyl silaketal groups tethered via a chiral, non-racemic 1,3-butanediol auxiliary proceeded in unexpected stepwise cycloadditions through ionic intermediates to provide cis-disubstituted bicylolactones. The ratio of two isomers, exo and endo, was 5 to 1, and each isomer was found to be diastereomerically pure (>99% de). Their relative and absolute stereochemistries were determined by $^1H$ NMR spectroscopy and confirmed by X-ray crystallography of minor, endo-adduct 9. The major exo-adduct was successfully transformed to (-)-2-butyl substituted A-ring phophine oxide 16, a key element for the synthesis of 2-butyl vitamin D3.

Photochemical C$_4$-Cycloadduct Formation between 5(E)-Styryl-1,3-dimethyluracil and Some Olefins-Via Photochemical Diels-Alder Type [4 + 2] Adduct

  • Shim, Sang-Chul;Shin, Eun-Ju
    • Bulletin of the Korean Chemical Society
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    • v.8 no.5
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    • pp.376-380
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    • 1987
  • The cyclobutane forming photocycloaddition reaction of 5(E)-styryl-1,3-dimethyluracil with some olefins occurs on the 5,6-double bond of uracil ring rather than the expected central double bond via an intermediate, probably the photochemical Diels-Alder type adduct. This intermediate formed on short term irradiation of 5(E)-styryl-1,3-dimethyluracil and 2,3-dimethyl-2-butene solution is converted into the $C_4$-cycloadduct on the prolonged irradiation. Quantum yield of the intermediate formation is not linear with the concentration of 2,3-dimethyl-2-butene probably due to the secondary reaction accompanied with the complex reaction kinetics. The intermediate is formed from the lowest excited singlet state.

Diels-Alder type adducts from the fruits of Morus alba L. (오디(Morus alba fruit)로 부터 Diels-Alder형 부가체 화합물의 분리 및 동정)

  • Lee, Yeong-Geun;Seo, Kyeong-Hwa;Hong, Eock-Kee;Kim, Dong-Man;Kim, Young-Eon;Baek, Nam-In
    • Journal of Applied Biological Chemistry
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    • v.59 no.2
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    • pp.91-94
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    • 2016
  • The fruits of Morus alba L. were extracted with 80 % aqueous MeOH, and the concentrated extract was partitioned into EtOAc, n-butyl alcohol, and water fractions. The repeated silica gel ($SiO_2$) and octadecyl silica gel column chromatographies for the EtOAc and n-butyl alcohol fractions led to isolation of two phenolic compounds. The chemical structures of the compounds were determined as Diels-Alder type adducts, mulberrofuran E (1) and chalcomoracin (2) based on spectroscopic data analyses including nuclear magnetic resonance, mass spectrometry, and infrared spectrometry. Compounds 1 and 2 were isolated for the first time from the fruits of M. alba L. in this study.

Diels-Alder Type Adducts from Hairy Root Cultures of Morus macroura

  • Happyana, Nizar;Hakim, Euis H.;Syah, Yana M.;Kayser, Oliver;Juliawaty, Lia D.;Mujahidin, Didin;Ermayanti, Tri M.;Achmad, Sjamsul A.
    • Natural Product Sciences
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    • v.25 no.3
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    • pp.233-237
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    • 2019
  • Three Diels-Alder type adducts, guangsangon E (1), chalcomoracin (2) and sorocein I (3) were isolated from hairy root cultures of Morus macroura. The structures of the isolated compounds (1-3) were determined by spectroscopic method (NMR and MS), and spectral comparison to literature. Cytotoxic activities of the isolated compounds (1 - 3) were investigated against P-388 murine leukemia cell line. Guangsangon E (1) showed the most potent cytotoxicity against P-388 murine leukemia cell line with $IC_{50}$ value of $2.75{\pm}0.32{\mu}g/mL$. To the best of our knowledge, guangsangon E (1) and sorocein I (3) were reported for the first time from the tissue cultures of M. macroura.

Synthesis of an Environmentally Friendly Phenol-Free Resin for Printing Ink

  • Ha, Young-Baeck;Jin, Ming Yu;Oh, Sung-Sang;Ryu, Do-Hyun
    • Bulletin of the Korean Chemical Society
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    • v.33 no.10
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    • pp.3413-3416
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    • 2012
  • Phenol-free resin was synthesized and its printing ink properties were investigated. The phenol-free resin was produced by esterification of poly phthalate and Diels-Alder adduct of rosin anhydride. Compared to rosin modified phenolic resin, eco-friendly phenol-free resin showed better vehicle properties in terms of gloss, yellowing, runability, and storage stability. The results suggest the utility of phenol-free resin instead of conventional rosin modified phenolic resin.