Studies on the molecular toxicology of buta-1,3-diene and isoprene epoxides.

Reactions of ethenyloxirane with amino (RNH2) and thiol (R'SH) nucleophiles occur by an SN2 mechanism involving competing ring cleavage at C-2 and C-3. In contrast, 2-ethenyl-2-methyloxirane reacts with amino (RNH2) and thiolate (R'S-) nucleophiles in methanol by regioselective SN2 attack at C-3 ("neo-pentyl" position). However, in pure water or methanol SN1 reaction occurs mainly at C-2.