$1033.00 - $3101.00
Boc-Thr(Fmoc-Ala)-OH is a protected Thr/Ala building block in which the Thr side-chain oxygen is acylated by Fmoc-Ala. Independent structural records for CAS 909115-21-5 confirm this O-acyl connectivity, with Boc on the Thr amino group and Fmoc on the Ala amino group.
This is therefore not an ordinary linear Thr-Ala dipeptide. It is a protected depsipeptide / O-acyl isopeptide-type intermediate whose O-linked topology is the central procurement feature.
Product Information
| Product Name | Boc-Thr(Fmoc-Ala)-OH |
| Catalog No. | AS4192 |
| CAS No. | 909115-21-5 |
| Molecular Formula | C27H32N2O8 |
| Molecular Weight | 512.56 g/mol |
| Building Block Type | Protected Thr O-acyl-Ala depsipeptide / O-acyl isopeptide building block |
| Primary Applications | O-acyl peptide chemistry; protected depsipeptide intermediates; specialized fragment synthesis; difficult-sequence route development |
Why O-Acyl Connectivity Matters
An ester bond through the Thr side-chain oxygen has different stability and migration behavior from a conventional N-linked peptide bond. Formula and molecular weight alone cannot distinguish these topologies, so the structural drawing should be checked before use.
Dual Boc/Fmoc Protection Provides Directional Control
The Thr nitrogen is Boc-protected while the Ala nitrogen is Fmoc-protected. This creates differentiated temporary protecting groups that can support route-specific manipulation, but the order of deprotection must be planned carefully.
Use in Specialized Peptide Assembly
O-acyl Ser/Thr intermediates are used in selected depsipeptide and O-acyl isopeptide strategies. Their value is often related to temporary backbone reorganization or specialized fragment assembly. Whether O-to-N acyl transfer is desired depends on the specific route and should not be assumed for every use.
Procurement and QC
Confirm CAS 909115-21-5, C27H32N2O8, MW 512.56 g/mol, the Thr O-Ala ester linkage, Boc protection on Thr, and Fmoc protection on Ala. An exact structure is more informative than the abbreviated product name.
For difficult sequences or O-acyl isopeptide route design, the building block should be evaluated with the complete synthesis plan through custom peptide synthesis.
Product Documents
A Safety Data Sheet (SDS / MSDS) is available for this product to support laboratory handling, storage and safety assessment.
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 Boc-Thr(Fmoc-Ala)-OH a normal Thr-Ala dipeptide?
No. The Ala acyl group is attached through the Thr side-chain oxygen.
Which amino group is Boc-protected?
The Thr amino group is Boc-protected; the Ala amino group is Fmoc-protected.
Why is the exact connectivity important?
O-linked and N-linked Thr/Ala structures have different chemistry despite related compositions.
Related Technical Resources
Review protected peptide assembly in SPPS