Trifluoromethanesulfonic anhydride–4-(N,N-dimethylamino)pyridine as a reagent combination for effecting Bischler–Napieraiski cyclisation under mild conditions: application to total syntheses of the Amaryllidaceae alkaloids N-methylcrinasiadine, anhydrolycorinone, hippadine and oxoassoanine

Abstract

A combination of triflic anhydride and 4-(N,N-dimethylamnino)pyridine effects Bischler–Napieraiski cyclisation of β-phenethytearbamates and β-phenethylamides under very mild conditions.