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

Reactions of ethenyloxirane with amino (RNH(2)) and thiol (R'SH) nucleophiles occur by an S(N)2 mechanism involving competing ring cleavage at C-2 and C-3. in contrast, 2-ethenyl-2-methyloxirane reacts with amino (RNH(2)) and thiolate (R'S-) nucleophiles in methanol by regioselective S(N)2 attack at C-3 (''neo-pentyl'' position). However, in pure water or methanol S(N)1 reaction occurs mainly at C-2.