Abstract
2-Propenyl- and 2-(2-methylpropenyl)-1,3-dioxane react with 2 equiv. of sec-butyllithium complexed with potassium tert-butoxide in tetrahydrofuran (THF) at –95 °C undergoing a 1,4 eliminative ring fission with subsequent proton abstraction at the α vinyl site of the enol ethers produced; carbanions obtained undergo substitution and addition reactions with electrophiles.