Related Experiment Video
Updated: Oct 9, 2026

Production and Testing of Antimicrobial Peptides and Their Mimics
Published on: April 10, 2026
Asymmetric synthesis of a 3-acyltetronic acid derivative, RK-682, and formation of its calcium salt during silica gel
1Institute for Chemical Reaction Science, Tohoku University, Sendai, Miyagi, Japan. sodeoka@icrs.tohoku.ac.jp
Abstract:
RK-682 was reported to be a potent protein tyrosine phosphatase inhibitor. We found that (R)-3-hexadecanoyl-5-hydroxymethyltetronic acid (1) was easily converted to its calcium salt during column chromatography on Silica gel 60, and this calcium salt was identical to RK-682 originally isolated from a natural source. Here we report details of the asymmetric synthesis of (R)-1 and its conversion to the calcium salt. Fast atom bombardment mass spectrometric (FAB-MS) analysis of the free and calcium salt forms of RK-682 is also reported.
Related Concept Videos
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...
Alkylation of β-Diester Enolates: Malonic Ester Synthesis
Alkylation of β-Ketoester Enolates: Acetoacetic Ester Synthesis
Silica Gel Column Chromatography: Overview
Polar components tend to bind strongly to the silica gel, causing them to move slowly through the column. In contrast, nonpolar compounds...
Acid Halides to Carboxylic Acids: Hydrolysis
As shown below, the mechanism involves a nucleophilic attack by water at the carbonyl carbon to form a tetrahedral intermediate. This is followed by the reformation of the carbon–oxygen π bond along with the departure of a halide ion. A final proton transfer step yields carboxylic acid...
Preparation of Carboxylic Acids: Carboxylation of Grignard Reagents
