Treatment of 2,3-epoxyalkyl chlorides with potassium tert-butoxide affords the corresponding (E)-1-chloro-3-hydroxyalkenes stereoselectively when dicyclohexano-18-crown-6 is present. On the other hand, 2,3-epoxyalkyl phenyl ethers furnish (E)-3-hydroxy-1-alkenyl phenyl ethers stereoselectively upon exposure to n-butyllithium in the presence of hexamethylphosphoric triamide.
Takano Seiichi, Sugihara Yoshiaki, Ogasawara Kunio, Heterocycles, 39 (1994) N 1, S 59-66