Scope of the pyrone transformation with diamines 2^a.

Bis-adduct	Ar	R	Yield from enaminone 3, % (Method A)	Yield from diamine, % (Method B)	5E,5′E-4 : 5E,5′Z-4
4a	Ph	H	64	57	50 : 17
4b	4-MeOC6H4	H	73	38	69 : 17
4c	4-ClC6H4	H	65	75	39 : 26
4d	2-Th	H	75	31	71 : 14
4e	2-Th	Me	79	63	74 : 10

^aMethod A: pyrone 1 (0.26 mmol) and enaminone 3 (0.26 mmol) were stirred in EtOH (2 mL) at 20 °C for 24 h. Method B: pyrone 1 (0.72 mmol) and diamine 2 (0.36 mmol) were stirred in EtOH (2 mL) at 0 °C for 1 h and then at 20 °C for 24 h.