Name: Hydroxy-PEG4-t-butyl ester
Brand: BOC Sciences
Rating: 5 (1 reviews)

Size

Price

Stock

Quantity

$--

In stock

Purity

≥95%

Solubility

Soluble in DCM, DMSO, Water

Appearance

Colorless to light yellow to light orange clear liquid

Storage

Store at 2-8°C

Shipping

Room temperature, or blue ice upon request.

IUPACName

tert-butyl 3-[2-[2-[2-(2-hydroxyethoxy)ethoxy]ethoxy]ethoxy]propanoate

Synonyms

HO-PEG4-CH2CH2COOtBu; Hydroxy-PEG4-(CH2)2-Boc; OH-PEG4-TBA; OH-PEG4-CH2CH2COOtBu; HO-PEG4-t-butyl ester; tert-Butyl 1-hydroxy-3,6,9,12-tetraoxapentadecan-15-oate; 15-Hydroxy-4,7,10,13-tetraoxapentadecanoic acid tert-butyl ester; 2-Methyl-2-propanyl 1-hydroxy-3,6,9,12-tetraoxapentadecan-15-oate; 3,6,9,12-Tetraoxapentadecan-15-oic acid, 1-hydroxy-, 1,1-dimethylethyl ester

Boiling Point

406.8±35.0 °C at 760 mmHg

Density

1.047±0.1 g/cm3

InChI Key

FJRDXEGYAVAMLB-UHFFFAOYSA-N

InChI

InChI=1S/C15H30O7/c1-15(2,3)22-14(17)4-6-18-8-10-20-12-13-21-11-9-19-7-5-16/h16H,4-13H2,1-3H3

SMILES

CC(C)(C)OC(=O)CCOCCOCCOCCOCCO

Biological Activity

Hydroxy-PEG4-(CH2)2-Boc is a uncleavable ADC linker used in the synthesis of antibody-drug conjugates (ADCs). Hydroxy-PEG4-<br/>(CH2)2-Boc is extracted from patent WO2004008101A2 (compound 191). In Vitro: ADCs are comprised of an antibody to which is<br/>attached an ADC cytotoxin through an ADC linker.

This Hydroxy-PEG4-t-butyl ester linker is designed to provide a hydrophilic polyethylene glycol segment while incorporating a protected carboxyl functionality suitable for PROTAC assembly. Its PEG-based architecture can enhance aqueous compatibility and tune linker flexibility, supporting efficient conjugation between ligand moieties. The protected ester enables controlled late-stage functionalization, facilitating reproducible synthesis workflows; detailed structural and reactivity considerations are provided below.

Structure: The linker contains a polyethylene glycol chain bearing a terminal hydroxy group and a t-butyl ester-protected carboxylate. It features ether linkages within the PEG segment, an ester linkage at the protected terminus, and a hydroxyl handle for orthogonal coupling strategies. Overall, it is polar and conformationally flexible.

Reactivity: The t-butyl ester can be selectively deprotected under acid-promoted conditions to reveal a carboxylic acid for amide or ester bond formation. Coupling to amine-bearing ligands is commonly performed via carbodiimide-mediated activation in suitable polar solvents, often with base to promote nucleophilic acyl substitution. The hydroxy group can be used for further derivatization using standard activation chemistries, enabling modular PROTAC construction.

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* Our calculator is based on the following equation:
Concentration (start) x Volume (start) = Concentration (final) x Volume (final)
It is commonly abbreviated as: C₁V₁ = C₂V₂