C-Sulfonyldithioformates as heterodienophiles and enophiles in [4 + 2] cycloaddition and ene reactions

Abstract

C-Sulfonyldithioformates 3 have been shown to be super-heterodienophiles in [4 + 2] cycloadditions with acyclic and cyclic dienes. Acyclic 1,3-dienes react with 3 in chloroform at room temperature to give the corresponding dihydrothiopyrans 4–6, while cyclopentadiene reacts with 3 to afford endo- and exo-2-thiabicyclo[2.2.1]heptene 7. Furthermore, the enophilic properties of 3 have been demonstrated by reacting 3 with tetramethylallene, 1-butene and trans-2-butene to afford the corresponding ene adducts 9, 10 and 11 respectively in quantitative yields.