group in the equatorial position perpendicular of the seven membered ring plane of 1, is the most stable con formation of N (cycloheptatrien 7 yl) phthalimide, which is 3.5 kcal/mol more favorable than conformation 5 with the phthalimido substituent in the axial position. The cal culated barrier Δ to the inversion of the seven membered ring (1→ 5) through transition state (TS) 3, with the almost flat cycloheptatriene ring, is rather low (5.5 kcal/mol), which is ...
