Home
Products
PROTAC Linker
m-PEG4-C6-phosphonic acid ethyl ester

m-PEG4-C6-phosphonic acid ethyl ester

Name: m-PEG4-C6-phosphonic acid ethyl ester
Brand: BOC Sciences
Rating: 5 (1 reviews)

CAS No.: 2028281-89-0

Cat No.: BP-500619

Purity: ≥95% 4.5

m-PEG4-C6-phosphonic acid ethyl ester is a heterobifunctional PROTAC linker featuring a methoxy-terminated PEG4 chain connected to a six-carbon spacer bearing a phosphonic acid ethyl ester. Structurally, the PEG segment provides conformational flexibility and aqueous solubility, while the C6 spacer length helps tune the spatial relationship between the two binding elements of a degrader. The phosphonate functionality serves as a chemically addressable handle for constructing linker–warhead conjugates, enabling controlled attachment to partners through phosphonate-derived coupling strategies commonly used in targeted degradation workflows. In PROTAC design, such linkers are used to optimize productive ternary complex formation by adjusting reach and orientation between the ligand that recruits the E3 ligase and the ligand that binds the target protein. This product is valuable for researchers seeking modular, water-compatible linker architectures to systematically evaluate how linker length, polarity, and reactive functional groups influence degradation efficiency and selectivity.

Structure of 2028281-89-0

Quality
Assurance

Worldwide
Delivery

24/7 Customer
Support

Category

PROTAC Linker

Molecular Formula

C19H41O7P

Molecular Weight

412.50

Appearance

Pale Yellow Oily Matter

* For research and manufacturing use only. Not for human or clinical use.

Size	Price	Stock	Quantity
--	$--	In stock

Looking for different specifications? Click to request a custom quote!

Capabilities & Facilities

Comprehensive PROTAC Platform
Scientific Expertise & Technical Support
Custom Synthesis & Design Service
Extensive Product Coverage

Cutting-Edge Innovation
Fast Delivery & Global Support
24/7 customer service
100% quality assurance

Popular Publications Citing BOC Sciences Products

Purity

≥95%

Appearance

Pale Yellow Oily Matter

Storage

Store at 2-8°C

Shipping

Room temperature in continental US; may vary elsewhere.

IUPACName

1-diethoxyphosphoryl-8-[2-[2-(2-methoxyethoxy)ethoxy]ethoxy]octane

Synonyms

m-PEG4-(CH2)8-phosphonic acid ethyl ester; Diethyl (2,5,8,11-tetraoxanonadecan-19-yl)phosphonate; Phosphonic acid, P-9,12,15,18-tetraoxanonadec-1-yl-, diethyl ester; Diethyl 2,5,8,11-tetraoxanonadecan-19-ylphosphonate

Boiling Point

479.0±35.0°C (Predicted)

Density

1.019±0.06 g/cm3 (Predicted)

InChI Key

CNDORYGJXMHDBX-UHFFFAOYSA-N

InChI

InChI=1S/C19H41O7P/c1-4-25-27(20,26-5-2)19-11-9-7-6-8-10-12-22-15-16-24-18-17-23-14-13-21-3/h4-19H2,1-3H3

SMILES

CCOP(=O)(CCCCCCCCOCCOCCOCCOC)OCC

1. Production and biological function of volatile esters in Saccharomyces cerevisiae

Sofie M G Saerens, Freddy R Delvaux, Kevin J Verstrepen, Johan M Thevelein Microb Biotechnol. 2010 Mar;3(2):165-77.doi: 10.1111/j.1751-7915.2009.00106.x.Epub 2009 Apr 6.

The need to understand and control ester synthesis is driven by the fact that esters play a key role in the sensorial quality of fermented alcoholic beverages like beer, wine and sake. As esters are synthesized in yeast via several complex metabolic pathways, there is a need to gain a clear understanding of ester metabolism and its regulation. The individual genes involved, their functions and regulatory mechanisms have to be identified. In alcoholic beverages, there are two important groups of esters: the acetate esters and the medium-chain fatty acid (MCFA) ethyl esters. For acetate ester synthesis, the genes involved have already been cloned and characterized. Also the biochemical pathways and the regulation of acetate ester synthesis are well defined. With respect to the molecular basis of MCFA ethyl ester synthesis, however, significant progress has only recently been made. Next to the characterization of the biochemical pathways and regulation of ester synthesis, a new and more important question arises: what is the advantage for yeast to produce these esters? Several hypotheses have been proposed in the past, but none was satisfactorily. This paper reviews the current hypotheses of ester synthesis in yeast in relation to the complex regulation of the alcohol acetyl transferases and the different factors that allow ester formation to be controlled during fermentation.

2. Single-crystal-to-single-crystal phase transition of 18β-glycyrrhetinic acid isopropyl ester

Dominik Langer, Barbara Wicher, Ewa Tykarska Acta Crystallogr B Struct Sci Cryst Eng Mater. 2022 Jun 1;78(Pt 3 Pt 2):450-458.doi: 10.1107/S2052520622002517.Epub 2022 Apr 30.

Due to the destruction of the integrity of the parent crystal, single-crystal-to-single-crystal phase transition in organic compounds is still a relatively rare phenomenon. The phase transition in glycyrrhetinic acid isopropyl ester is triggered by temperature change. The increasing volume of the isopropyl substituent as a result of increasing temperature forces a remodelling of the structural motifs. These changes cause a single-crystal-to-single-crystal phase transition. The low-temperature form is isostructural with glycyrrhetinic acid methanol solvate, while the high-temperature phase is isostructural with the ethyl ester of this acid.

m-PEG4-C6-phosphonic acid ethyl ester is a PEG-based, flexible linker designed to support targeted protein degradation (PROTAC) architectures by providing controlled spacing and solubility between a ligand and an E3-recruiting warhead. Its phosphonate ethyl ester functionality enables downstream functionalization to generate reactive handles for conjugation strategies commonly used in PROTAC synthesis. The following sections describe its structure and the practical reactivity considerations relevant to linker incorporation in PROTAC workflows.

Structure: The linker combines a polyethylene glycol segment with a phenyl-hexyl spacer and a phosphonate ethyl ester group. It contains ether linkages within the PEG chain, aromatic C–C bonds in the phenyl ring, and a phosphonate P–O framework with an esterified oxygen. Overall, it is expected to display amphiphilic, water-compatible behavior.

Reactivity: Phosphonate ethyl esters are typically transformed under nucleophilic substitution or hydrolysis conditions to access phosphonic acid derivatives used for coupling or further derivatization. For PROTAC assembly, conjugation is commonly approached via activation of the phosphonate (or conversion to the acid) followed by esterification or amide-forming coupling, depending on the partner functional group. Mild base or acid hydrolysis and standard coupling chemistries are generally employed, with polar aprotic solvents often used to maintain solubility and reaction efficiency.

Stock concentration: *

Desired final volume: *

Desired concentration: *

* 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