N-α-Fmoc-N-ε-1-(4,4-dimethyl-2,6-dioxocyclohex-1-ylidene)ethyl-D-lysine is a D-lysine-derived amino acid derivative bearing an N-terminal Fmoc protecting group and an ε-amino side chain modified as a cyclic imide/ketone-type ylidene adduct with a 4,4-dimethyl-2,6-dioxocyclohex-1-ylidene substituent. The molecule contains both an α-amino functional group protected as Fmoc and a carboxyl group, while the lysine ε-nitrogen is incorporated into the substituted side-chain functionality that alters nucleophilicity and provides a defined handle for controlled chemical transformations. In peptide chemistry and chemical biology workflows, this protected, side-chain-modified lysine analogue is used as a building block for stepwise incorporation into peptide intermediates and for structure-activity or labeling studies where modulation of the lysine side-chain reactivity is required.
CAT No: CP01440
N-α-Fmoc-N-ε-1-(4,4-dimethyl-2,6-dioxocyclohex-1-ylidene)ethyl-D-lysine is an Fmoc-protected D-lysine derivative in which the α-amino group is masked as an Fmoc carbamate while the ε-amino functionality is converted into a substituted, cyclic imide-like enamine/ylidene-protected form bearing a 4,4-dimethyl-2,6-dioxocyclohex-1-ylidene motif. The molecule retains the lysine side-chain carbon framework and carboxylate present as a protected or derivatizable acid functionality consistent with peptide building block chemistry, while the D stereocenter at the lysine backbone enables stereochemically defined incorporation into peptide sequences and stereocontrolled analogs. The bulky, electron-withdrawing cyclic group on the ε-nitrogen is designed to modulate nucleophilicity and suppress undesired side reactions during coupling, while the Fmoc group provides orthogonal base-labile deprotection for stepwise solid-phase synthesis. The resulting reactivity profile supports peptide coupling at the α-position after Fmoc removal, and the protected ε-nitrogen can be unmasked under compatible conditions to enable downstream side-chain functionalization or further derivatization.
1. Peptide Synthesis
N-α-Fmoc-N-ε-1-(4,4-dimethyl-2,6-dioxocyclohex-1-ylidene)ethyl-D-lysine serves as a stereodefined lysine building block for peptide assembly in research-grade peptide synthesis workflows. The Fmoc-protected α-amino group supports standard peptide coupling chemistry after base-mediated Fmoc deprotection, while the ε-amino is protected by the 4,4-dimethyl-2,6-dioxocyclohex-1-ylidene-derived group to reduce competing side reactions during chain elongation. The D-lysine stereochemistry enables access to D-amino acid-containing peptides used for conformational control, protease resistance studies, and sequence-specific analog design. The protected ε-nitrogen can be selectively revealed or transformed to generate lysine side-chain functionalities in later synthetic steps, enabling iterative construction of peptide scaffolds and peptidomimetic libraries.
2. Side-Chain Functionalization
N-α-Fmoc-N-ε-1-(4,4-dimethyl-2,6-dioxocyclohex-1-ylidene)ethyl-D-lysine is suitable for amino acid derivatization strategies targeting lysine side-chain chemistry while maintaining orthogonal protection. The ε-amino protection with the cyclic 4,4-dimethyl-2,6-dioxocyclohex-1-ylidene motif helps control nucleophilicity during peptide coupling, allowing selective conversion of the side chain after the peptide backbone is assembled. The retained lysine carbon skeleton provides a handle for introducing functional groups such as amide, urea, carbamate, or conjugation-ready linkers following ε-deprotection or transformation. Downstream use can include preparation of functional peptide analogs for chemical biology, linker installation for bioconjugation, and generation of side-chain-modified intermediates for SAR-focused molecular design.
3. Bioconjugation Chemistry
N-α-Fmoc-N-ε-1-(4,4-dimethyl-2,6-dioxocyclohex-1-ylidene)ethyl-D-lysine supports bioconjugation workflows that require controlled lysine reactivity and defined stereochemistry. The Fmoc group enables stepwise incorporation into peptide carriers, while the protected ε-nitrogen helps prevent premature conjugation during synthesis and purification steps. The D-lysine backbone can be leveraged to construct conjugates with altered proteolytic stability and conformational behavior, which is relevant for labeling reagents, affinity probes, and chemically defined biomolecule scaffolds. The protected ε-amino functionality can be unmasked to generate a reactive amine for coupling to activated esters, isothiocyanates, aldehyde-derived linkers, or other electrophiles used in biomolecule labeling and conjugate construction.
4. SAR Studies
N-α-Fmoc-N-ε-1-(4,4-dimethyl-2,6-dioxocyclohex-1-ylidene)ethyl-D-lysine is applicable to structure-activity relationship studies where stereodefined lysine analogs are used to map binding determinants and conformational preferences. The combination of D stereochemistry at the lysine center and orthogonal protection at both α- and ε-nitrogen positions supports systematic variation of peptide length, side-chain modification patterns, and terminal functionalization. The Fmoc handle enables consistent peptide coupling across analog series, while the ε-protecting cyclic group helps maintain uniform side-chain availability until the intended diversification step. Resulting analogs can be used as chemically comparable probes for receptor/target interaction mapping, fragment-to-peptide refinement, and SAR-driven optimization of peptidomimetic scaffolds in medicinal chemistry research settings.
5. Pharmaceutical Manufacturing
N-α-Fmoc-N-ε-1-(4,4-dimethyl-2,6-dioxocyclohex-1-ylidene)ethyl-D-lysine can be employed in process chemistry and manufacturing-oriented synthesis of protected amino acid intermediates for peptide-based active ingredient precursors. The Fmoc protection strategy supports robust, base-triggered deprotection logic compatible with stepwise production of peptide intermediates, while the ε-amino cyclic protection can mitigate side reactions that would otherwise complicate scale-up and purification. The defined D-lysine stereochemistry enables reproducible incorporation into stereochemically specified peptide sequences used in industrial fine chemical production. The compound's protected functional groups facilitate controlled downstream transformations into peptide building blocks and intermediate streams that can feed into larger manufacturing sequences for peptide analogs and peptidomimetic drug candidates.
6. Fine Chemical Synthesis
N-α-Fmoc-N-ε-1-(4,4-dimethyl-2,6-dioxocyclohex-1-ylidene)ethyl-D-lysine is suitable for fine chemical synthesis where orthogonally protected amino acid derivatives are required as chiral intermediates. The Fmoc-protected α-amino group and protected ε-nitrogen provide a chemically addressable framework for sequential functional group manipulation, enabling construction of customized lysine-containing intermediates for synthetic methodology development. The cyclic 4,4-dimethyl-2,6-dioxocyclohex-1-ylidene motif can function as a temporary nitrogen-protecting element that controls amine reactivity during multi-step sequences. Downstream utility includes preparation of labeled or functionalized peptide fragments, generation of chiral building blocks for heterocycle or linker synthesis, and support for analytical standard development requiring stereochemically defined lysine derivatives.
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