Biomimetic Total Syntheses of (+)-Chloropupukeananin, (−)-Chloropupukeanolide D, and Chloropestolides

• DOI: 10.1021/acs.joc.1c02108
• Publication Date: 2021-10-21T12:52:30Z
• Authors: Takahiro Suzuki; Soichiro Watanabe; Wataru Ikeda; Susumu Kobayashi; Keiji Tanino
• Keywords: Biomimetic Synthesis; Chemical Sciences not elsewhere classified; Cycloaddition Reaction; diels – alderase; biomimetic total syntheses; 540; Biochemistry; 3. Good health; Inorganic Chemistry; herein report; Sociology; Biomimetics; Total Synthesis; Medicine; enzymes involved; (+)- chloropupukeananin; Natural Products; pot biomimetic synthesis; chloropupukeananin family involves; chloropupukeananin family; Diels-Alder reaction; Sesquiterpenes; Biotechnology; Biological Sciences not elsewhere classified; Organic Synthesis and Reactions

The biomimetic total synthesis of (+)-chloropupukeananin (overall 4.5% yield, 19 steps from pyrone 22) and (−)-chloropupukeanolide D via an intermolecular Diels-Alder reaction using (−)-maldoxin and (+)-iso-A82775C and an intramolecular carbonyl-ene reaction has been achieved. Moreover, the biomimetic synthesis of chloropestolides H-K using (−)-maldoxin and siccayne unveiled the solvent effect of the intermolecular Diels-Alder reaction. The origin of the stereoselectivity of the intermolecular Diels-Alder reaction is still elusive; however, the biosynthesis of the chloropupukeananin family should involve enzymes that catalyse the intermolecular Diels-Alder reaction.