Ac-L-Leu-OMe contains the L-leucine amino acid backbone in an N-acetylated, methyl ester form, where the side chain is the isobutyl group characteristic of leucine and the molecule retains the alpha carbon stereochemistry indicated by the L designation. The structure bears an N-acetyl amide functionality and a carboxylate methyl ester, replacing the free amino and free carboxyl groups found in unprotected amino acids and thereby reducing nucleophilicity at those termini while keeping the backbone geometry consistent for peptide-related transformations. Ac-L-Leu-OMe is used as an amino acid derivative and peptide precursor in solution-phase or solid-phase synthesis workflows, where ester and amide protection support controlled coupling and downstream conversion to more complex leucine-containing amide or peptide structures.
CAT No: CP25377
CAS No:1492-11-1
Synonyms/Alias:MethylN-acetyl-L-leucinate;1492-11-1;AC-LEU-OME;N-Acetylleucinemethylester;IIGAKARAJMXVOZ-QMMMGPOBSA-N;ZINC00399125;Methyl2-(acetylamino)-4-methylpentanoate#;AmbotzAAA1921;N-Acetyl-L-Leu-OMe;AC1OCUS6;Acetyl-L-Leucinemethylester;CHEMBL58991;SCHEMBL5812880;N-Acetyl-L-leucinemethylester;CTK8B8578;MolPort-008-267-307;ZINC399125;L-Leucine,N-acetyl-,methylester;ANW-60739;AKOS006272050;VZ33077;Leucine,N-acetyl-,methylester,L-;AJ-21712;AK-81090;KB-257895
Chemical Name:N-alpha-Acetyl-L-leucine methyl ester
Ac-L-Leu-OMe is an N-acetylated, methyl ester derivative of L-leucine, combining an amide-capped amino terminus with an esterified carboxyl group. This neutral, protected form is commonly used as a defined leucine building block in peptide and peptidomimetic synthesis workflows where controlling termini reactivity is essential. Its leucine side chain supports incorporation into hydrophobic peptide segments, while the capped termini help minimize side reactions during downstream coupling or segment assembly.
1. Peptide Segment Building
Ac-L-Leu-OMe is frequently used in peptide synthesis as a leucine-containing segment precursor where the N-terminus is already acetylated and the C-terminus is present as a methyl ester. Researchers performing solution-phase or fragment condensation workflows select this derivative to keep the amino group non-nucleophilic and to maintain a controlled activation state at the ester end during sequential assembly steps. This makes it a practical choice for preparing defined oligopeptide intermediates, especially when the target sequence requires leucine at a specific position without introducing additional terminal functional groups.
2. Peptidomimetic Intermediate Synthesis
Ac-L-Leu-OMe also serves as a convenient intermediate for constructing peptidomimetic scaffolds that retain leucine-like hydrophobic character while using protected termini to steer synthetic selectivity. Medicinal chemistry and process development teams often rely on amino acid ester derivatives like this one to build libraries of short peptidomimetics or to generate well-defined intermediates for further functional group interconversions. The N-acetyl and methyl ester pattern provides a stable, isolable form that can be carried through multi-step synthesis before conversion to the corresponding amide or acid functionality required for the final analog.
3. Controlled Substrate and Standard Preparation
Ac-L-Leu-OMe is used in chemical biology and analytical chemistry settings to prepare defined leucine-based substrates and reference materials where a specific terminal protection pattern is required. By providing an N-acetylated amide and an esterified carboxyl group, the compound offers a consistent structural motif for evaluating or calibrating assay workflows that depend on terminal reactivity states rather than free amino and carboxyl groups. Laboratories preparing internal standards, method development samples, or comparative substrates for ester/amide-related transformations often choose this derivative to reduce variability introduced by uncontrolled termini.
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