Fmoc-Asn(Xan)-OH is Nα-Fmoc-Nβ-xanthyl-L-asparagine. Xanthyl protection masks the Asn side-chain amide nitrogen while the α-amino group uses standard Fmoc protection.

Its value is selective control of the Asn side chain during coupling and chain elongation, especially when an unprotected side-chain amide contributes to route-specific impurity formation.

Product Information

Application Scope in Asn-Containing Peptides

Xan-protected Asn is useful for sequences where a protected side-chain amide improves route robustness, including fragment work and difficult SPPS. It provides an alternative to Trt-type Asn protection with a distinct steric and acid-lability profile.

Protection Strategy and Sequence Context

The Fmoc/Xan combination is compatible with base-mediated Fmoc cycles and acid-mediated global deprotection. Selection should be made against the full protection map and the SPPS workflow, not solely by substituting one Asn reagent for another.

Procurement and QC

Confirm CAS 185031-78-1, C32H26N2O6, MW 534.57 g/mol, L stereochemistry and Nβ-xanthyl protection. Exact protection position is more informative than formula or mass alone.

Use lot-specific COA/HPLC/MS data when Asn-derived impurities are a major project risk.

Product Documents

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

Fmoc-Asn(Xan)-OH 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

What does Xan protect in this reagent?

The Asn side-chain amide nitrogen.

Is this the D-Asn analog?

No. CAS 185031-78-1 corresponds to the L-Asn derivative.

Can it be used in Fmoc-SPPS?

Yes, with a protection/deprotection scheme compatible with the full sequence.

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