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Updated: Dec 28, 2025

A Direct, Early Stage Guanidinylation Protocol for the Synthesis of Complex Aminoguanidine-containing Natural Products
Published on: September 9, 2016
Asymmetric Total Synthesis of (-)-Guignardones A and B
Zhiming Yan1, Chunbo Zhao1, Jianxian Gong1
1State Key Laboratory of Chemical Oncogenomics, Key Laboratory of Chemical Genomics , Peking University Shenzhen Graduate School , Shenzhen 518055 , China.
Abstract:
The asymmetric total synthesis of (-)-guignardones A (2) and B (1) has been accomplished. The highly oxidized 6-oxabicyclo[3.2.1]octane core was constructed from d-quinic acid via substitution/desulfurization reaction with thiophenol to forge the bridged ring scaffold, and a Pummerer rearrangement and 1,4-addition/elimination sequence was employed to install the β-carbonyl group at the congested C-1 position. A late-stage Knoevenagel condensation-6π-electrocyclization and directed hydrogenation formed (-)-guignardone B (1), which was subjected to dehydration to furnish (-)-guignardone A (2).
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