Ether, methyl propenyl metallation

Alkyl enol ethers can be conveniently prepared by the alkylation of a-methoxyvinyllithium and related metallated enol ethers. In a typical example, methyl vinyl ether (1) is converted by r-butyllithium to give a-methoxyvinyllithium (2). Reaction of (2) with octyl iodide gives the enol ether (3). Metallation of methyl propenyl ether (4) and methyl allenyl ether (5) can be similarly executed. ... 

Pure di-2-propenylzinc2,8,9 10, bis(2-methyl-2-propenyl)zinc11 or di-2-butenylzinc11 are best prepared by the metal exchange between dimethylzinc and the appropriate triallylborane, which is produced in situ from the Grignard reagent and boron trifluoride-diethyl ether complex. The purification is accomplished by distillation, for experimental procedure, see ref 2, p619. 

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