Hamiltonian algorithm and its application to the aromatic oxidative cyclization on N-methoxy-N-prenylbenzamide

The geometric structures of the phenoxenium cation which is a cation intermediate of 2-azaspiro ring compounds (2-azaspiro[4.5]decane) from N-methoxy-N-prenylbenzamide are studied by means of the Hamiltonian algorithm with ab intio molecular orbital calculations at HF/3-21G level. The geometries are further refined with MP2/6-311G** level. We tried four substituted compounds with the methyl group. Among them only one compound with two methyl groups gives a ring-closure intermediate, which agrees well with the experimental results.