Product Number: E034005
English Name: Eldecalcitol Impurity 5
English Alias: (5R,6R)-6-((R)-1-((tert-butyldimethylsilyl)oxy)-5-((4-methoxybenzyl)oxy)pent-3-yn-1-yl)-2,2,3,3,12,12,13,13-octamethyl-5-vinyl-4,7,11-trioxa-3,12-disilatetradecane
CAS Number: 2569209-09-0
Molecular Formula: C₃₈H₇₀O₆Si₃
Molecular Weight: 707.22
As an impurity of Eldecalcitol, this compound has the following advantages:
Well-defined with distinct protecting group features: Contains multiple silyl ethers (tert-butyldimethylsilyl, octamethyl disiloxane), 4-methoxybenzyl (PMB) ether, alkyne, and vinyl groups. Strong hydrophobicity from silyl/PMB moieties creates significant polarity differences from eldecalcitol, enabling accurate identification via GC or normal-phase HPLC as a specific impurity marker;
High stability and traceability: Dual protection of hydroxyls by silyl/PMB ethers ensures extreme stability under non-acidic conditions. As an intermediate from incomplete deprotection or cyclization in eldecalcitol synthesis, it directly reflects efficiency of deprotection/cyclization steps, improving process tracing accuracy;
High detection sensitivity: UV absorption (210-230nm) from alkyne/vinyl unsaturation, combined with silicon-specific mass responses (e.g., Si(CH₃)₃ fragments), enables trace analysis (ppm level) via GC-MS or LC-MS, compatible with multi-protected vitamin D precursor impurity systems.
Pharmaceutical quality control: Used as an impurity reference standard to quantify Eldecalcitol Impurity 5 in APIs, ensuring residual protected intermediates meet quality standards post-deprotection/cyclization;
Synthesis optimization: Optimizing PMB/silyl deprotection (acid concentration) and alkyne cyclization parameters by monitoring impurity levels to enhance steroid ring formation efficiency;
Intermediate purity assessment: Evaluating purity of key multi-protected intermediates in eldecalcitol synthesis to support specificity of downstream cyclization/oxidation.
Eldecalcitol, an active vitamin D₃ analog, requires multi-step hydroxyl protection (silyl/PMB), alkyne coupling, and cyclization for steroid skeleton construction. Incomplete deprotection or blocked alkyne cyclization may generate protected/uncyclized derivatives like Eldecalcitol Impurity 5. Its interference with cyclization efficiency and lack of bioactivity make control critical for eldecalcitol quality assurance.
Current research focuses on:
Analytical method validation: Developing GC-MS assays with methylsiloxane columns for baseline separation of impurity and intermediates, achieving 0.5 ppm detection limits;
Deprotection kinetics: Studying impurity formation under varying deprotecting reagents to clarify synergistic removal mechanisms of silyl/PMB groups;
Cyclization process refinement: Controlling impurity levels below 0.1% via optimized ruthenium-catalyzed cyclization to enhance API purity;
Stereochemical confirmation: Using 2D-NMR to verify (5R,6R) configuration, supporting structural differentiation from eldecalcitol precursors
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