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Enantioselective synthesis of alpha-benzoxy-alpha-alkylmalonate via Phase-transfer Catalytic alkylation : 상전이 촉매 알킬화 반응을 통한 alpha-benzoxy-alpha-alkylmalonate 의 입체선택적 합성
DC Field | Value | Language |
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dc.contributor.advisor | 박형근 | - |
dc.contributor.author | 김식 | - |
dc.date.accessioned | 2017-07-19T11:19:21Z | - |
dc.date.available | 2017-07-19T11:19:21Z | - |
dc.date.issued | 2015-02 | - |
dc.identifier.other | 000000025044 | - |
dc.identifier.uri | https://hdl.handle.net/10371/133559 | - |
dc.description | 학위논문 (석사)-- 서울대학교 대학원 : 약학과, 2015. 2. 박형근. | - |
dc.description.abstract | Chiral alpha-hydroxy malonates and their equivalents are potentially valuable intermediates for the synthesis of natural products and pharmaceuticals. alpha-Hydroxy malonate itself can be easily modified to chiral glycerols or alpha,alpha-dihydroxy esters according to the chemical conversion of two esters. There have been a lot of enantioselective synthetic methods of alpha-hydroxy-β-ketoesters. However, they have been mostly achieved by the enzymatic desymmetrization of prochiral malonates.
Recently, our research team reported a new synthetic method of chiral alpha,alpha-dialkylmalonates in high chemical yields and enantioselectivities by phase-transfer catalytic (PTC) desymmetrization of malonates in the presence of chiral quaternary ammonium salts, and successfully proved its usefulness by applications to the synthesis of various chiral building blocks bearing quaternary carbon center. Based on this study, highly enantioselective alkylation of tert-butyl diphenylmethyl alpha-benzoxymalonate could be accomplished under phase-transfer catalysis in the presence of (S,S)-3,4,5-trifluorophenyl-NAS bromide as PTC catalyst to afford the corresponding alpha-benzoxy-alpha-alkylmalonates in high chemical (up to 99%) and optical yields (up to 93% ee) which could be readily converted to versatile chiral intermediates. | - |
dc.description.tableofcontents | INTRODUCTION
1. Character of -acyloxy--alkylmalonate compound 2. Phase-transfer Catalysis for asymmetric alkylation 2.1 Phase-transfer Catalysis 2.2 Progress of phase-transfer catalytic alkylation 2.2.1. Progress of phase-transfer catalysts 2.2.2. Progress of substrates for phase-transfer catalytic alkylation RESULT AND DISCUSSION 1. Substrate design and preparation for PTC alkylation 2. Enantioselective phase-transfer catalytic reaction of -benzoxymalonate 2.1. Optimization of PTC reaction of -benzoxymalonate 2.2. Enantioselective PTC alkylation with various alkyl halides 2.3. Limitation of -benzoxymalonate in enantioselective phase-transfer catalytic Michael reaction 3. Application and determination of absolute configuration CONCLUSION EXPEIMENTAL SECTION 1. General methods 1.1. Solvents and reagents 1.2. Chromatography and HPLC 1.3. Spectral data 2. α-acyloxy-α-alkylmalonates 2.1 Preparation of α-acyloxymalonate substrate 2.2 General procedure for asymmetric phase-transfer catalytic alkylation REFERENCES APPENDIX 국문초록 | - |
dc.format | application/pdf | - |
dc.format.extent | 1588754 bytes | - |
dc.format.medium | application/pdf | - |
dc.language.iso | en | - |
dc.publisher | 서울대학교 대학원 | - |
dc.subject | Enantioselective synthesis | - |
dc.subject | phase-transfer catalysis | - |
dc.subject.ddc | 615 | - |
dc.title | Enantioselective synthesis of alpha-benzoxy-alpha-alkylmalonate via Phase-transfer Catalytic alkylation | - |
dc.title.alternative | 상전이 촉매 알킬화 반응을 통한 alpha-benzoxy-alpha-alkylmalonate 의 입체선택적 합성 | - |
dc.type | Thesis | - |
dc.description.degree | Master | - |
dc.citation.pages | 54 | - |
dc.contributor.affiliation | 약학대학 약학과 | - |
dc.date.awarded | 2015-02 | - |
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