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Updated: Jun 20, 2026

A Direct, Early Stage Guanidinylation Protocol for the Synthesis of Complex Aminoguanidine-containing Natural Products
Published on: September 9, 2016
Total Syntheses of Proposed Structures of 4,10-Dihydroxy-8,12-guaianolides
Yuki Kimura1, Eisaku Ohashi1, Sangita Karanjit1
1Graduate School of Pharmaceutical Sciences, Tokushima University, 1-78-1 Shomachi, Tokushima 770-8505, Japan.
Abstract:
The first total syntheses of two 4,10-dihydroxy-8,12-guaianolides that were reported to be natural products were achieved. Toward the syntheses of a collection of related guaianolides, the typical 5,7-fused system of 8,12-guaianolides was constructed by a ring expansion reaction of a hydroxylated coronafacic acid analogue that can be practically synthesized and optically resolved. The total syntheses of these compounds revealed that the previously reported structures of both natural products were incorrect.
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