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Updated: Oct 17, 2025

A Direct, Early Stage Guanidinylation Protocol for the Synthesis of Complex Aminoguanidine-containing Natural Products
Published on: September 9, 2016
Enantiodivergent Synthesis of Benzoquinolizidinones from L-Glutamic Acid
Punlop Kuntiyong1, Duangkamon Namborisut1, Kunita Phakdeeyothin1
1Department of Chemistry, Faculty of Science, Silpakorn University, Muang Nakhon Pathom 73000, Thailand.
Abstract:
Benzoquinolizidinone systems were synthesized in both enantiomeric forms from L-glutamic acid. The key chiral arylethylglutarimide intermediate was synthesized from dibenzylamino-glutamate and homoveratrylamine. Aldol reaction of the glutarimide afforded a mixture of syn and anti-aldol adducts. Subsequent regioselective hydride reduction of the glutarimide carbonyl followed by N-acyliminium ion cyclization afforded a product with opposite absolute configurations at C3 and C11b. Cope elimination of the dibenzylamino group then converted the two diastereomers into enantiomers.
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