Previously1 we described a reaction of 2-alkynyl ethers and alkali amides in liquid ammonia leading to 3-alken-1-ynes in high yields.Bis-2-alkynyl ethers (R1 = -CHzC=CCHzR, I) also undergo the 1 ,Celimination reaction but here the yields of the enynes are moderate because of a peculiar side-reaction leading to a furan. The isolated 3,4-disubstituted furans I11 (yields 20-30 %), which are isomeric with the starting materials, may be the result of a base-catalyzed cyclization of intermediary bis-1 ,2-alkadienyl ethers 11 (another possibility is cyclization of RCHz-CH=C=CH -0-CHz-C = C-CHzR and subsequent isomerization of the resulting 3-alkylidene-4-(l-alkenyI)-2,3-dihyd; -\furan).