Reaction of 5-aryloxazolidines with arylmagnesium bromides as a new route to N-benzyl-β-hydroxyphenethylamines as starting materials for the preparation of 4-aryl-1,2,3,4-tetrahydroisoquinolines

Benzaldehydes react smoothly with the non-stabilized azomethine ylide derived from sarcosine and formaldehyde to form 5-aryloxazolidines as intermediates, which undergo ring-opening to give N-benzyl-β-hydroxyphenethylamines in good yields by the action of arylmagnesium bromides. Their subsequent acid-catalyzed cyclization into 4-aryl-1,2,3,4-tetrahydroisoquinolines was performed in moderate to good yields.