Product Information

Product Number: E034011

English Name: Eldecalcitol Impurity 11

English Alias: ((Z)-2-((3R,4S,5R)-4,5-bis((tert-butyldimethylsilyl)oxy)-3-(3-((tert-butyldimethylsilyl)oxy)propoxy)-2-methylenecyclohexylidene)ethyl)diphenylphosphine oxide

CAS Number: 1809782-28-2

Molecular Formula: C??H??O?PSi?

Molecular Weight: 771.24

Advantages

Well-defined with prominent functional groups: Contains three tert-butyldimethylsilyl (TBS) groups, diphenylphosphine oxide (DPPO), (Z)-ethylidene side chain, and propoxy moieties. Combined hydrophobicity of silyl groups and polarity of phosphine oxide enable distinct retention behavior from eldecalcitol, allowing accurate identification via normal-phase HPLC/LC-MS as a specific impurity marker;

High stability and traceability: TBS-mediated hydroxyl protection and chemical stability of phosphine oxide ensure stability across wide pH ranges. As an intermediate from residual Wittig phosphine reagents, incomplete desilylation, or blocked cyclization, it directly reflects efficiency of phosphine-coupling steps, improving process tracing accuracy;

High detection sensitivity: Strong UV absorption (250-270nm) from (Z)-alkene-benzene conjugation, combined with phosphorus isotope (31P) and silicon-specific mass responses (e.g., m/z 772 [M+H]?), enables trace analysis (ppb level) via LC-MS/MS, compatible with silyl-protected/phosphine-containing vitamin D precursor systems.

Applications

Pharmaceutical quality control: Used as an impurity reference standard to quantify Eldecalcitol Impurity 11 in APIs, ensuring residual phosphine/silylated intermediates meet quality standards post-Wittig reaction/desilylation/cyclization;

Synthesis optimization: Optimizing DPPO reagent dosage, Wittig reaction conditions (base strength), and TBS deprotection by monitoring impurity levels to enhance alkene formation efficiency;

Intermediate purity assessment: Evaluating purity of key phosphine-substituted alkene intermediates in eldecalcitol synthesis to support specificity of downstream cyclization/oxidation.

Background Description

Research Status

Analytical method validation: Developing UPLC-MS/MS assays with phosphorus fragment monitoring (e.g., m/z 201 [Ph?PO]?) for simultaneous quantification of impurity and intermediates, achieving 0.1 ppb detection limits;

Wittig reaction kinetics: Studying impurity formation under varying phosphine reagent ratios to clarify correlations between DPPO and alkene selectivity;

Process refinement: Controlling impurity levels below 0.05% via optimized Wittig reaction parameters to enhance API purity;

Structural characterization: Using 31P-NMR and 2D-NMR to verify (3R,4S,5R) configuration and (Z)-geometry, supporting structural differentiation from eldecalcitol precursors.