Lithium diisopropylamide in the presence of catalytic amounts of potassium tert-butoxide smoothly converts homoallyl or homobenzyl type ethers to dienes egeg, 1, 3, 5, 26 or styrenes (2). γ, δ-Unsaturated acetals give 13-dienyl ethers eg, 4 and 4- alkylidenetetrahydropyrans or dihydropyrans produce a variety of dienols (eg, 6–17, 20–22).- If there is a choice, the new double bond is formed with high trans-selectivity while the ...