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Updated: Feb 17, 2026
![Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F60786.jpg&w=3840&q=50)
Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions
Published on: July 17, 2020
Asymmetric Total Syntheses and Structure Confirmation of Chlorofucins and Bromofucins
Byungsook Kim1, Te-Ik Sohn1, Deukjoon Kim1
1College of Pharmacy, Seoul National University, Seoul, 151-742, Korea.
Abstract:
Substrate-controlled asymmetric total syntheses and structure confirmation of (+)-(3E)- and (-)-(3Z)-chlorofucin [(E)-1 a and (Z)-1 a], and (+)-(3E)- and (-)-(3Z)-bromofucin [(E)-1 b and (Z)-1 b] were accomplished. Our syntheses feature as key steps haloetherification (either 'conventional' or 'one-pot organoselenium-mediated') of α,α'-trans-γ,δ-unsaturated oxocene alcohol 9 and our (E)- and (Z)-selective cross-metathesis (CM) protocols. More importantly, a rationale is provided for the strikingly different pathways followed by α,α'-trans-γ,δ-unsaturated oxocene alcohol 9 and its α,α'-cis isomer 9' in the presence of different electrophiles during the intramolecular electrophilic addition reactions.
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