(2a-zc) were prepared and treated with potassium t-butoxide (KO-t-Bu) in boiling tetrahydrofuran (THF). The principal products obtained from the methyl, ethyl, and isopropyl ethers (la-le) were the corresponding 2, 5-dihydrofuran (3), 2-methyl-3-l-butoxy-3- alkoxypropene (5), and 2-t-butoxymethyl-3-alkoxypropene (6). The t-butyl ether If gave 1- methylene-2-t-butoxycyclopropane (7) as the only cyclic product, together with the ...