Total synthesis of (+/-)-galanthamine via a C3-selective Stille coupling and IMDA cycloaddition cascade of 3,5-dibromo-2-pyrone.

A new efficient synthetic route to (+/-)-galanthamine was devised by using a tandem C3-selective Stille coupling-IMDA cascade of 3,5-dibromo-2-pyrone as a key strategy.

The decarboxylative Blaise reaction.

Reaction of aryl nitriles with potassium ethyl malonate in the presence of zinc chloride and a catalytic amount of Hünig's base provided beta-amino acrylates in moderate to good yield. Compared to the classical Blaise reaction, this reaction is safer (endothermic), devoid of lacrimatory reagent, and is possible with 0.5-1.