8-Methxlcorxpallihe and its O-Metbzlzzher: A Facile Sxhthesis of 8-Methxl Substituted-6, 7- Dimethoxy Tetrahsdroisoquxnolines

Abstract

The optically active B-Methy1 substituted tetrahydroisoquinoline (−)− 1 is a major reaction product in the cleavage of the bisbenzylisoquinoline alkaloid repanduline with potassium in liquid ammonia.¹ A synthesis of (±) − 1 by a rather lengthy procedure has been reported.² In this connection we now wish to report a simple and efficient method of introducing an 8-methyl substituent into a 7-hydroxy-6- methoxy tetrahydroisoquinoline. This approach, which has probably wider applications, is exemplified by the synthesia of 8-methylcorypalline 4 and its O-methylether 5 and involves the thiomethylation reaction of poppeladorf and Holt³ followed by reductive desulfurization of the phenyl thiomethyl intermediate.