Related Experiment Video
Updated: Aug 17, 2026
![Solid-phase Synthesis of [4.4] Spirocyclic Oximes](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F58508.jpg&w=3840&q=50)
Solid-phase Synthesis of [4.4] Spirocyclic Oximes
Published on: February 6, 2019
Synthesis of alpha-, beta- and cyclic spaglumic acids
1Vittal Mallya Scientific Research Foundation, Bangalore, India.
Abstract:
A short, one-pot synthesis of alpha- and beta-spaglumic acids (N-acetyl-L-aspartyl-L-glutamic acids, NAAGA) has been developed based on ultrasound-promoted acetylation of aspartic acid, followed by dehydration, condensation with glutamic acid dibenzyl ester and hydrogenolysis. The alpha- and beta-peptides were separated by anion-exchange chromatography. The alpha-peptide shows a remarkable tendency to cyclize during methylation with diazomethane and yields cyclic N-acetylaspartylglutamic acid dimethyl ester, which could be hydrolysed to the hitherto unreported diketopiperazine dicarboxylic acid, cyclic spaglumic acid (cyclic NAAGA).
Related Concept Videos
α-Halogenation of Carboxylic Acid Derivatives: Overview
Preparation of Acid Anhydrides
The carboxylate ion acts as a nucleophile that attacks the carbonyl carbon of the acid chloride to form a tetrahedral intermediate. Subsequently, the re-formation of the carbonyl group with the loss of the chloride ion as a leaving group leads to the formation of an acid...
α-Bromination of Carboxylic Acids: Hell–Volhard–Zelinski Reaction
Preparation of 1° Amines: Gabriel Synthesis
Strong bases like NaOH or KOH deprotonate the phthalimide to form the corresponding anion, which acts as a nucleophile. Further, the anion attacks an...
Alkylation of β-Ketoester Enolates: Acetoacetic Ester Synthesis
Alkylation of β-Diester Enolates: Malonic Ester Synthesis

