The use of Reissert compounds as intermediates for the synthesis of 1-benzylisoquinolines has been investigated. An improved method, utilising sodium hydride, for the generation of the carbanion of Reissert compounds and subsequent reaction with benzyl halides has been found and demonstrated to be a general procedure. This method has been successfully applied as the key stage in providing a new total synthesis of the alkaloid petaline. The stereochemistry of the Reissert compound system has been elucidated by spectroscopic techniques.