Generation of 2-substituted-2-metallo-1,3-dithianes and their coupling with 1,2-disubstituted epoxides at room temperature

2-Substituted-1,3-dithianes were subjected to lithiation by n-BuLi at room temperature and the resulting anions reacted with 1,2-disubstituted epoxides at room temperature, giving the coupling products in satisfactory yield. In addition, a mixed organometallic reagent, n-BuLi/Bu₂Mg, was found to be an effective metallation reagent for 2-substituted-1,3-dithianes.