• 제목/요약/키워드: Deprotection

검색결과 61건 처리시간 0.033초

An Efficient Method for Selective Deprotection of Trimethylsilyl Ethers and Tetrahydropyranyl Ethers under Solvent-free Conditions

  • Hajipour, A.R.;Bagheri, Hamid R.;Ruoho, Arnold E.
    • Bulletin of the Korean Chemical Society
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    • 제26권11호
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    • pp.1689-1691
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    • 2005

  • 1-Butyl-4-aza-1-azoniabicyclo[2.2.2]octane dichromate (BAABOD) 3 is a useful reagent for the selective cleavage of trimethylsilyl ethers and tetrahydropyranyl ethers to their corresponding aldehydes and ketones in the presence of $AlCl_3$ under solvent-free conditions. This method is very simple and efficient and the reaction has been carried out under solvent-free conditions in the presence of a catalytically amount of aluminum chloride.

  • https://doi.org/10.5012/bkcs.2005.26.11.1689 인용 PDF KSCI

Synthesis of 4-(2-thiazolyloxy)phenylalkanoic Acids As An An-tiinflammatory Agent

  • Choi, Hong-Dae;Shin, Sang-Hoon;Son, Byeng-Wha
    • Archives of Pharmacal Research
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    • 제19권2호
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    • pp.148-152
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    • 1996

  • The efficient synthesis of 4-(2-thiazolyloxy)phenylalkanoic acids (10a-c), which are a potent antiinflammatory agent, was achieved in 5-6 steps starting from isopropoxybenzene and methyl $\alpha-chloro-\alpha-(methylthio)acetate (1)$. The key intermediate (4) was prepared by Friedel-Crafts reaction of isopropoxybenzene with (1) followed by desulfurization and the removal of isopropyl protector. Methyl 4-hydroxyphenylalkanoates (6, 8) were similarly obtained from alkylation of (3) and deprotection.

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Synthesis of Polymers Having N-Hydroxymaleimide Units by Thermolysis of N-(Isopropyloxycarbonyloxy)maleimide Polymers

  • 안광덕
    • Bulletin of the Korean Chemical Society
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    • 제16권5호
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    • pp.443-449
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    • 1995

  • N-(Isopropyloxycarbonyloxy)maleimide (iPOCMI) has been synthesized and polymerized to give both the homopolymer and copolymers with substituted styrenes. These polymers were readily deprotected by thermolysis of the isopropyloxycarbonyl (iPOC) groups to provide the corresponding N-hydroxymaleimide (HOMI) polymers. The homopolymer and styrenic copolymers of iPOCMI were radically obtained in higher conversion and higher molecular weight than those obtained by direct polymerizations of N-hydroxymaleimide. The homopolymer of iPOCMI was transformed into poly(N-hydroxymaleimide)P(HOMI) by thermolysis of iPOC groups at 205 $^{\circ}C$ with concurrent release of propene and carbon dioxide. The copolymer of iPOCMI and styrene was thermally deprotected to the copolymer of HOMI and styrene at 235 $^{\circ}C.$ The mass loss was 28% and the Tg of the resulting copolymer was 250 $^{\circ}C.$ The thermal deprotection readily provided the desired, polar HOMI polymers which have Tgs above 240 $^{\circ}C.$ The deprotection was accompanied by large changes in aqueous base solubility.

  • https://doi.org/10.5012/bkcs.1995.16.5.443 인용 PDF