[摘要]：A competitive multicomponent synthesis of tetrahydrobenzo[b]pyrans over polyhydroquinolines is achieved in the presence of ammonium acetate at ambient temperature in ethanol medium. The formation of tetrahydrobenzo[b]pyran instead of polyhydroquinoline in solution phase has been confirmed by spectral and single-crystal analysis. The mechanism for the above transformation is suggested and supported by semi-empirical calculations of heat of formation for the intermediates as well as products. |
