A density functional theory approach toward substituent effect in Meerwein-Eschenmoser-Claisen rearrangement.

B3LYP/6-31 G(d) level of theory has been used for the examination of substituent effect in the concerted step of the Meerwein-Eschenmoser-Claisen rearrangement. In this regard, the effect of NO(2) and NH(2) groups in different positions has been investigated. The obtained results show that substituent effect is very sensitive to its position and configuration. Electron withdrawing and electron donating groups in different positions and various configurations show different and sometimes opposite results.