Ethers with the systems , CH3CCCH(OR)2, CH3CCCH(OR)3 or ‐CH2‐CH2‐CCOR undergo an elimination of ROH [R = alkyl, 2‐alkynyl (‐CH2CC‐R′) phenyl, or 2‐tetrahydropyranyl] with formation of 1,3‐enyne derivatives, , on treatment with alkali amides in liquid ammonia.
The cyclic ethers: and are isomerized under these conditions to the 1,3‐enyne carbinols HCC‐CHC(CH3)CH2OH and HCC‐CHCH(CH2)4OH.