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DOI: 10.1055/a-2736-0204
Total Synthesis of Denigrins D and E, and Formal Synthesis of Polycitones A and B
Authors
We acknowledge the financial support from the Science and Engineering Research Board, New Delhi, through a research grant (CRG/2022/001698).
Dedication
Dedicated to Prof. S. Chandrasekaran on the occasion of his 80th birthday.
Abstract
We report here the concise total syntheses of the densely substituted pyrrole-containing, marine-derived alkaloids denigrins E and D, together with the formal syntheses of polycitones A and B. Starting from p-methoxydibenzyl ketone, denigrin E was obtained in just two steps (44% overall yield), while denigrin D was synthesized in three steps (26% overall yield). In addition, the Steglich synthon, a key intermediate toward polycitones A and B, was accessed in three steps (34% overall yield), thus completing the formal synthesis of polycitones A and B. The overall efficiency of this route arises from the key transformation: a microwave-assisted Paal–Knorr pyrrole synthesis.
Keywords
Marine natural product - Total synthesis - Denigrins E & D - Formal synthesis - Polycitone A & B - Microwave - Paal–Knorr SynthesisPublication History
Received: 29 September 2025
Accepted after revision: 31 October 2025
Article published online:
18 November 2025
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