title: A practical synthesis of chiral tricyclic cyclopenta[b]benzofuran, a key intermediate of Beraprost.
abstract: A novel formal synthesis of Beraprost (1) is described. The tricyclic cyclopent[b]benzofuran core is efficiently prepared from (-)-Corey lactone diol in 12 steps with an overall yield of 37.4%. Key features of the strategy include a ring-closing metathesis reaction and aromatization to form the tricyclic cyclopenta[b]benzofuran framework, and selective halogenation/formylation to install the butyrate side-chain.
authors.affiliation: State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica, Beijing Key Laboratory of Active Substances Discovery and Druggability Evaluation, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing 100050, PR China. xp@imm.ac.cn.
authors.forename: Xiaoyu
authors.initials: X
authors.lastname: Liu
authors.affiliation: Department of Medicinal Chemistry, Key Laboratory of Chemical Biology (MOE), School of Pharmacy, Shandong University, Jinan, Shandong 250012, China. tiancs@thelilab.cn.
authors.forename: Chengsen
authors.initials: C
authors.lastname: Tian
authors.affiliation: State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica, Beijing Key Laboratory of Active Substances Discovery and Druggability Evaluation, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing 100050, PR China. xp@imm.ac.cn.
authors.forename: Xiaozhen
authors.initials: X
authors.lastname: Jiao
authors.affiliation: State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica, Beijing Key Laboratory of Active Substances Discovery and Druggability Evaluation, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing 100050, PR China. xp@imm.ac.cn.
authors.forename: Xiaoyu
authors.initials: X
authors.lastname: Li
authors.affiliation: State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica, Beijing Key Laboratory of Active Substances Discovery and Druggability Evaluation, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing 100050, PR China. xp@imm.ac.cn.
authors.forename: Hongguang
authors.initials: H
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica, Beijing Key Laboratory of Active Substances Discovery and Druggability Evaluation, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing 100050, PR China. xp@imm.ac.cn.
authors.forename: Yangyang
authors.initials: Y
authors.lastname: Yao
authors.affiliation: State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica, Beijing Key Laboratory of Active Substances Discovery and Druggability Evaluation, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing 100050, PR China. xp@imm.ac.cn.
authors.forename: Ping
authors.initials: P
authors.lastname: Xie
mesh_terms: D001572:Benzofurans / Q000138:chemical synthesis* / Q000737:chemistry; D003517:Cyclopentanes / Q000138:chemical synthesis* / Q000737:chemistry; D011464:Epoprostenol / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry; D015394:Molecular Structure
chemical_list: D001572:Benzofurans; D003517:Cyclopentanes; C048081:beraprost; D011464:Epoprostenol