[2,3]-Wittig rearrangement by a chlorine–lithium exchange

The reaction of different allylic chloromethyl ethers 1 with an excess of lithium powder (1:7 molar ratio) and a catalytic amount of DTBB (2.5 mol %) in THF at 0 °C for 1 h gives, after hydrolysis with water, the expected alcohols 2 resulting from a [2,3]-Wittig rearrangement, in an exclusive manner. The same process can also be applied to the corresponding [1,2]-Wittig rearrangement, as it is exemplified for benzyl chloromethyl ether.