Bromo- l- trimethylsilyloxy ethylene

Solubility sol Et20, THE and most organic solvents fairly sol cold water. 

Preparative Methods addition of bromine to trimetbylsilyl vinyl ether in CH2CI2 or Et20 at —60 °C, followed by dehydrobromi-nation with triethylamine (50%) or by reaction of trimethylsi-lyl 2,2-dibromoethyl ether with two equiv of n-butyllithium in Et20 from —70 °C to rt (86%) ZJE 95I5)  

Handling, Storage, and Precaution must be stored at —20°C in the absence of moisture (flushing with dry Ar or N2). It turns pale yellow on storage. It is instantaneously hydrolyzed by dilute acidic aqueous solutions. 

It is noteworthy that compounds homologous with (1) couple with Grignard reagents in the presence of nickel-phosphine complexes to produce alkylated and arylated enol ethers (eq A)  

Reagent (1) has been condensed with allylic alcohols in the presence of a catalytic quantity of a Lewis acid (such as boron trifluoride etherate) to achieve a new synthesis of a./S-unsaturated aldehydes (eq 2). This reaction is analogous to the widely used Mtiller-Cunradi-Pieroh reaction except that the oxidation state of the cationic species is one unit lower and that of the nucleophilic species is one unit higher. Thus condensation with 8-ionol leads to an a-bromo aldehyde which was transformed into S-ionylideneacetaldehyde by dehydrobromination, using 1,8-diazabicyclo[5.4.0]undec-7-ene.  

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Z)-2-Bromo-l-(trimethylsilyloxy)ethylene 1 is used essentially as a precursor of (Z)-2-(trimethylsilyloxy)vinyllithium (eq 1).3... 

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