F'ropargyl ethers HCECCHaOR [R = alkyl or -CH(CHa)(OCaHa)] have been isomerized with good yields into the corresponding allenyl ethers CHa=C=CHOR by warming with potassium rert.-butoxide at 70 '. These allenyl ethers can be metallated with butyllithium in ether or alkali amides in liquid ammonia. In ether, subsequent alkylation with alkyl halides R'Hal affords a-substituted allenyl ethers CHs=C=C(R)OR. Alkylation in liquid ammonia produces a mixture of this ...
