• 제목/요약/키워드: Efficient cyclization

검색결과 39건 처리시간 0.024초

Mn(III)-Mediated Radical Cyclization for Δ1-3-Octalone Synthesis

  • Lee, Mi-Ai;Yang, Jae-Deuk;Kim, Moon-Soo;Jeon, Hye-Sun;Baik, Woon-Phil;Koo, Sang-Ho
    • Bulletin of the Korean Chemical Society
    • /
    • 제23권5호
    • /
    • pp.736-740
    • /
    • 2002
  • An efficient and practical synthetic method of △1 -3-octalone, which is a versatile building block for thesyntheses of polycyclic compounds, has been developed. The dianion of ethyl acetoacetate reacts with cyclohexene-1-carboxaldehyde (3) to produce the aldol adduct 6, which then undergoes Mn(Ⅲ)-mediated radical cyclization followed by acetate elimination to give △1 -3-octalone 4. A detailed mechanistic insight of Mn(Ⅲ)-mediated cyclization of 6 has been disclosed.

Total Synthesis of Fentanyl

  • Suh, Young-Ger;Cho, Kyung-Ho;Shin, Dong-Yoon
    • Archives of Pharmacal Research
    • /
    • 제21권1호
    • /
    • pp.70-72
    • /
    • 1998
  • Fentanyl of a potent anilidopiperidine analgesic has been synthesized from a simple phenyle-thylamine by four step sequence. The key part of this synthesis involves an efficient construc-tion of phenylethylpiperidone skeleton via aminomethano desilyation-cyclization followed by Swern oxidation.

  • PDF

Approach to the Total Synthesis of Acanthoside-D

  • Ngoc, Thyen-Truong;Park, Hae-Il
    • 대한약학회:학술대회논문집
    • /
    • 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
    • /
    • pp.186.4-187
    • /
    • 2003
  • Acanthoside-D, one of major components of Acanthopanacis Cortex, is known as a ginseng-like substance. it has been known to possess diverse biological effects. Acanthoside-D has a furofuran lignan structure and the synthesis of which poses interesting and often unsolved proplems of stereocontrol. Although a few interesting syntheses providing this natural product have been reported, an intermolecular McMurry coupling - intramolecular Mitsunobu cyclization route has not yet been explored. We report here a short and efficient synthetic pathway to the total synthesis of Acanthoside-D from aryl aldehydes and methyl acrylates via Baylis-Hillman reaction, intermolecular McMurry coupling and intramolecular Mitsunobu cyclization as key reaction.

  • PDF

Palladium-Catalyzed Cross-Coupling Reaction and Gold-Catalyzed Cyclization for Preparation of Ethyl 2-Aryl 2,3-Alkadienoates and α-Aryl γ-Butenolides

  • Mo, Jun-Tae;Hwang, Hoon;Lee, Phil-Ho
    • Bulletin of the Korean Chemical Society
    • /
    • 제32권spc8호
    • /
    • pp.2911-2915
    • /
    • 2011
  • Efficient synthetic method for the preparation of ethyl 2-aryl-2,3-alkadienoates through Pd-catalyzed selective allenyl cross-coupling reactions of aryl iodides with organoindiums generated in situ from indium and ethyl 4-bromo-2-alkynoate was developed. The cyclization reaction of ethyl 2-aryl-2,3-alkadienoates catalyzed by $AuCl_3$ and AgOTf in the presence of AcOH or TfOH produced various ${\alpha}$-aryl ${\gamma}$-butenolides or ${\gamma}$-substituted ${\alpha}$-aryl ${\gamma}$-butenolides.

An Efficient Synthesis of Substituted Furans by Cupric Halide-Mediated Intramolecular Halocyclization of 2-(1-Alkynyl)-2-alken-1-ones

  • Fu, Wei-Jun;Xu, Feng-Juan;Guo, Wen-Bo;Zhu, Mei;Xu, Chen
    • Bulletin of the Korean Chemical Society
    • /
    • 제34권3호
    • /
    • pp.887-891
    • /
    • 2013
  • An efficient synthesis of 3-halofurans by the intramolecular cyclization of 2-(1-alkynyl)-2-alken-1-ones with cupric halide has been developed. A broad range of 3-chloro- and 3-bromofuran derivatives could be obtained in the present method in moderate to good yields. The 3-halofuran derivatives are potential synthetic intermediates for amplification of molecular complexity.

A Facile and Efficient Synthesis of Dronedarone Hydrochloride

  • Li, Feng;Jin, Chunhua;Zou, Jianwei;Wu, Jun
    • Bulletin of the Korean Chemical Society
    • /
    • 제35권7호
    • /
    • pp.1970-1972
    • /
    • 2014
  • A facile and efficient synthesis of dronedarone hydrochloride starting from commercially available 4-nitrophenol is described. This approach features a tandem-type synthesis of 3-carbonylated benzofuran involving cyclization of 2-ethynylphenol followed by $CO_2$ fixation at the 3-position of the benzofuran ring mediated by potassium carbonate without the addition of any transition metal catalyst.

치환 다이페놀의 효율적 고리화 반응: 설퍼로다민B의 합성에의 응용 (Efficient Cyclization of Substituted Diphenols : Application to the Synthesis of Sulforhodamine B)

  • 박민균;심재진;나춘섭
    • 청정기술
    • /
    • 제21권2호
    • /
    • pp.102-107
    • /
    • 2015
  • Rhodamine염료는 높은 흡광계수와 함께 넓은 가시광선 영역에서 고효율과 안정성을 나타내는 형광을 제공함으로써 형광표지 물질로 널리 사용되고 있다. Rhodamine 화합물을 형광표지 물질로 이용하기 위해서는 rhodamine골격을 (생체)분자나 표면에 공유결합 시키는 화학적 과정이 필수적이기 때문에 이에 관련하여 다양한 rhodamine유도체를 합성해내는 효율적이고 실제적인 방법의 개발은 큰 관심을 끌어왔다. Sulforhodamine B는 반응성이 큰 두 개의 sulfoxy작용기를 포함하고 있는데 이를 이용하여 여러 재료에 공유결합 시킴으로써 널리 활용될 수 있는 유용한 화합물이다. 본 연구에서는 4-formyl-1, 3-benzenedisulfonic acid의 disodium염과 3-diethylaminophenol으로부터 3단계에 걸쳐 sulforhodamine B를 합성하는 과정을 연구하였다. 이 과정에서 dihydroxytriarylmethane 중간체를 xanthene 골격으로 전환하는 두 번째 단계를 획기적으로 개선하는 방법에 대해 기술하였다. 이는 반응 중에 생성되는 물분자가 역반응에 참여하는 것을 억제하도록 메탄올을 가함으로써 이루어졌다. 그 결과, 반응온도는 낮아지고(135에서 80 ℃), 수율은 크게 증가되었다(20% 미만에서 84%). 이로써, 기존의 3단계에 걸친 sulforhodamine B의 제법은 에너지 절감 및 자원효율 면에서 개선된 방법으로 이루어지게 되었다.