Fmoc-β-Iodo-L-Ala-OMe is N-Fmoc-3-iodo-L-alanine methyl ester. It combines an Fmoc-protected amino function, a reactive beta-iodomethyl side chain and a methyl-protected carboxyl group. Public chemical records list the stereochemical IUPAC form as (R)-methyl 2-((((9H-fluoren-9-yl)methoxy)carbonyl)amino)-3-iodopropanoate.

The methyl ester is a key practical detail. This material should not be treated like a routine Fmoc amino acid with a free carboxyl group ready for direct peptide-chain coupling. It is better viewed as a functionalized amino-acid intermediate for downstream chemical transformation.

Product Information

Why the Beta-Iodo Group Is Useful

An alkyl iodide is a reactive leaving-group handle that can participate in substitution or elimination chemistry when a route is designed for it. The actual downstream product depends on nucleophile, base, solvent and protection state. We therefore avoid presenting one transformation as the universal use of this reagent; the value is the controlled introduction of a beta-iodo handle into an enantiodefined alanine-derived scaffold.

The Methyl Ester Changes Peptide-Synthesis Readiness

Because the carboxyl group is methyl-esterified, the molecule is not directly equivalent to a free-acid Fmoc building block used in standard SPPS. A route may require ester hydrolysis or another transformation before conventional coupling. The standard Fmoc-SPPS workflow is a useful comparison point: routine monomers enter the cycle with a free carboxylate, whereas this intermediate carries a different activation state.

Stereochemistry and Iodine-Containing Identity

The product corresponds to L-alanine-derived stereochemistry even though the systematic name uses the R descriptor for this substituted structure. This is not contradictory; R/S assignment follows CIP priority. We recommend using the CAS, drawn structure and stereochemical record together rather than trying to infer L/D identity from the R/S label alone.

Procurement and QC Considerations

Confirm CAS 156017-42-4, formula C19H18INO4, MW 451.26 g/mol, beta-iodo substitution, Fmoc protection and methyl ester identity. Iodine contributes strongly to molecular mass, but MS alone still cannot establish stereochemistry or exclude positional isomers. Storage should minimize unnecessary light, heat and moisture exposure according to the lot-specific label.

Researchers planning to convert this intermediate into a noncanonical peptide residue can review Alan Scientific's unusual amino acids and analogs and, once the final residue and sequence are defined, custom synthesis of peptides containing transformed non-natural residues.

Product Documents

A Safety Data Sheet (SDS / MSDS) is available for this product to support laboratory handling, storage and safety assessment.

Fmoc-β-Iodo-L-Ala-OMe MSDS

Certificates of Analysis (COAs) are batch-specific. Please contact us to request the COA for your product, and we will provide it by email.

Frequently Asked Questions

Is Fmoc-β-Iodo-L-Ala-OMe ready for direct standard Fmoc-SPPS coupling?

Not as a conventional free-acid monomer. Its carboxyl group is protected as a methyl ester, so the route must account for that protection state.

What is the purpose of the beta-iodo group?

It provides a reactive alkyl-iodide handle for downstream functional-group transformation under route-specific conditions.

Why can an L-alanine derivative have an R systematic descriptor?

R/S notation depends on CIP priorities of the actual substituents; it does not map universally to L/D nomenclature.

Related Technical Resources

For the design rationale behind residues that depart from the 20 proteinogenic amino acids, read the noncanonical amino-acid design overview.

Research Use Only.