抄録
A predominant migration of γ-hydrogen atom of the propyl group has been observed in the fragmentation of the protonated propylacetate. In an attempt to explain this observation, MINDO/3 calculation has been carried out on the fragmentations that involve three to seven-membered ring transition states starting from the MH+ ions protonated at both keto and ether oxygen atoms. The results showed that hydrogen migration from β-position was energetically favorable and that the transition via 7-membered ring required higher potential energy to pass through.