• 제목/요약/키워드: Reductive cyclization

검색결과 11건 처리시간 0.021초

A Stereoselective Synthesis of 1 $\beta$-Aminocarbapenems.

  • 서경재;이태호;이연영
    • Bulletin of the Korean Chemical Society
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    • 제22권6호
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    • pp.553-558
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    • 2001

  • A stereoselective synthesis of $1\beta-aminocarbapenems$ (11a-c) starting from-4-acetoxy-2-axetidinone derivative 4 is described. 4-Acetoxy-2-azetidinone derivative (4) was reacted with lithium enolate of benzophenone limine of glycine phenyl ester (5f) to give alkylated product (R)-6f in good yield with high diastereoselectivity. The alkylated procudt (R)-6f was transformed to thioesters (7a-c) by transesterification with thiols, Thioesters (7a-c) were converted to their oxalimides (8a-c), followed by the phosphite-mediated reductive cyclization to give carbapenems (9a-c). Removal of all protecting groups of carbapenems (9a-c) afforded $1\beta-aminocarbapenems$ (11a-c).

  • https://doi.org/10.5012/bkcs.2001.22.6.553 인용 PDF

Synthesis of 2-Amino-4,6-Di-O-Benzoyl-3-O-Benzyl-1,2-Dideoxy Mannojirimycin

  • 조재익;윤신숙;천근호;Shin, Jeong E.
    • Bulletin of the Korean Chemical Society
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    • 제16권9호
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    • pp.805-808
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    • 1995

  • Diacetone-D-glucose was converted into 5-azido-6-O-benzoyl-3-O-benzyl-5-deoxy-1,2-O-isopropylidene-α-D-glucofuranose. After removal of isopropylidene and benzoyl protecting groups, hydrogenation performed reduction of azide and subsequent cyclization by reductive amination to give 3-O-benzyl-1-deoxy nojirimycin in high yield. The second azide group was introduced on 2-carbon by selective substitution reaction, and reduction of azide to amino group gave titled compound.

  • https://doi.org/10.5012/bkcs.1995.16.9.805 인용 PDF

Anticancer Agent인 Methotrexate에 대한 새로운 합성 연구 (A New Synthetic Studies on Anticancer Agent Methotrexate)

  • 유의경;류성렬
    • 대한화학회지
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    • 제37권1호
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    • pp.136-140
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    • 1993

  • 새로운 methotrexate 중간체인 diethyl N-[4-{[(2,4-diamino-6-yl)methyl]-amino}benzoyl]-L-glutamate(10)를 합성하기 위하여 p-nitrobenzoic acid를 chlorination한 다음 L-glutamic acid와 coupling하고 이를 esterification한 후, 환원과 methylation시켜 diethyl N-(4-methylaminobenzoyl)-L-glutamate(7)를 합성하였다. 이 화합물(7)을 DMF 존재하에서 NaH와 allyl chloride를 가하여 allylation한 다음 여기에 $IN_3$ addition 반응으로 diethyl-p-[N-(2-azido-3-iodopropyl)-N-methyl]aminobenzoyl-L-glutamate(9)를 합성하였다. 이 화합물(9)을 2,4,5,6-tetraaminopyrimidine hydrochloride와 cyclization시켜 methotrexate diethylester를 얻었다.

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Bulgecinine 선구물질인 (4S,5R)-1-Acetyl-2-formyl-5-benzyloxymethyl-4-pyrrolidinol의 합성 (Synthesis of a Precursor of Bulgecinine, (4S,5R)-1-Acetyl-2-formyl-5-benzyloxymethyl-4-pyrrolidinol)

  • 전학림;윤신숙;신영숙;남정이
    • 대한화학회지
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    • 제41권3호
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    • pp.150-156
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    • 1997

  • Bulgecinine의 선구물질인 (4S,5R)-1-acetyl-2-formyl-5-benzyloxymethyl-4-pyrrolidinol (15)을 diacetone-D-glucose로부터 합성하였다. Barton 탈산소화 반응, C-5에서의 반전, $-N_3$ 도입과 환원 및 C-2에서의 고리 형성을 통해 bulgecinine의 핵심 중간체인 두 고리 화합물 (6R)-6-Ο-benzyloxymethyl-(3R)-3-methoxy-2-oxa-5-azabicyclo-[2,2,1]heptane (13)을 합성하였다. 화합물 13을 N-아세틸화 후 산가수분해하여 얻은 bulgecinine 선구물질은 토토머화가 수반되어 (2S,4S,5R)-pyrrolidinol 유도체 15와 함께 (2S,4S,5R)-부분 입체 이성질체도 얻어졌다.

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