Synthesis 2023; 55(14): 2241-2252
DOI: 10.1055/s-0042-1752658
paper
Special Issue Honoring Prof. Guoqiang Lin’s Contributions to Organic Chemistry

Synthesis of Clausena Alkaloids Using Unique Ring Expansion of Dihydroisoquinolines and Their Cholinesterase Inhibitory Activity

Authors

  • Rattana Worayuthakarn

    a   Laboratory of Medicinal Chemistry, Chulabhorn Research Institute, 54 Kamphaeng Phet 6, Laksi, Bangkok 10210, Thailand
  • Chuleeporn Ngernnak

    a   Laboratory of Medicinal Chemistry, Chulabhorn Research Institute, 54 Kamphaeng Phet 6, Laksi, Bangkok 10210, Thailand
  • Somsak Ruchirawat

    a   Laboratory of Medicinal Chemistry, Chulabhorn Research Institute, 54 Kamphaeng Phet 6, Laksi, Bangkok 10210, Thailand
    b   Chemical Sciences Program, Chulabhorn Graduate Institute, Chulabhorn Royal Academy, 906 Kamphaeng Phet 6, Laksi, Bangkok 10210, Thailand
    c   Center of Excellence on Environmental Health and Toxicology (EHT), OPS, Ministry of Higher Education, Science, Research and Innovation, Bangkok 10400, Thailand
  • Kittipong Chainok

    d   Thammasat University Research Unit in Multifunctional Crystalline Materials and Applications (TUMCMA), Faculty of Science and Technology, Thammasat University, Pathumthani 12121, Thailand
  • Nanthawat Wannarit

    d   Thammasat University Research Unit in Multifunctional Crystalline Materials and Applications (TUMCMA), Faculty of Science and Technology, Thammasat University, Pathumthani 12121, Thailand
    e   Department of Chemistry, Faculty of Science and Technology, Thammasat University, Pathumthani 12121, Thailand
  • Nopporn Thasana

    a   Laboratory of Medicinal Chemistry, Chulabhorn Research Institute, 54 Kamphaeng Phet 6, Laksi, Bangkok 10210, Thailand
    b   Chemical Sciences Program, Chulabhorn Graduate Institute, Chulabhorn Royal Academy, 906 Kamphaeng Phet 6, Laksi, Bangkok 10210, Thailand
    c   Center of Excellence on Environmental Health and Toxicology (EHT), OPS, Ministry of Higher Education, Science, Research and Innovation, Bangkok 10400, Thailand

Funding: Thailand Science Research and Innovation (TSRI, Grant Number FRB660044/0240), Chulabhorn Royal Academy (Project Code 180874) and Chulabhorn Research Institute (Grant Numbers 36824/4274394 and 36827/4274407).


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Abstract

A facile and direct synthetic entry to the carbon skeleton of Clausena alkaloids, the benzo[d]azocin-4-one, is reported featuring the ring expansion of 1-phenyldihydroisoquinoline derivatives initially triggered by oxazolone under environmentally benign conditions in a one-pot procedure. Functionalization of the eight-membered lactam framework provided a set of Clausena alkaloid derivatives. Some derivatives show a promising inhibition toward acetylcholinesterase and a better selectivity index than the previously used Alzheimer’s disease (AD) drug, tacrine, and the currently used AD drug, galantamine.

Supporting Information



Publication History

Received: 31 January 2023

Accepted after revision: 24 February 2023

Article published online:
12 April 2023

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