Selective synthesis of mono- and bis-butenolide α-aminomethyl adducts

The selective installation of alpha-methylamine residues at the butenolide core is described using alpha-bromomethylene-.- butenolide and primary as well as secondary amines in methanol at 0 degrees C. The preparation of mono-and bis-butenolide alpha-adducts is described. Bis-gamma-butenolide adducts as well as mono alpha-aminomethyl-gamma-butenolides can be selectively obtained depending on the nature of the reacting primary amine. In contrast, the use of secondary amines allows two different pathways leading either to the expected amino derivatives or to the formation of a C-O bond.