Synthesis of Hydroxyalkyl Heterocyclesby Ring Transformation of Spiroepoxy Lactones with Binucleophiles

Abstract

Spiroepoxy lactones 2 and 3 were obtained by epoxidation of a-alkylidenelactones 1 with dimethyldioxirane. Reaction of spiroepoxy lactones 2 with binucleophiles gave access to a number of hydroxyalkyl heterocycles with interesting substituent patterns. Depending on both the kind of substituent at the oxirane ring as well as the type of the binucleophile, the spiroepoxy lactones react either as C 3 or as C 2 bielectrophilic building blocks giving 4-, 6-and 7membered partially saturated N-and S-heterocycles 5, 6, 8, 9, 11 and 13.