Methyl 5-(N, N-dimethylamino)-2, 4-pentadienoate (tert-aminodienylester 1) was synthesized by condensation of methyl crotonate (2) with N, N, N', N'-tetramethylmethylenediamine (3). The reactivity of 1 was investigated with methyl propiolate (4), dimethyl 2-butynedionate (5), dimethyl maleae (6), dimethyl fumarate (7), 2-buten-4-olide (8), 2-cyclohexenone (9), styrene (10), trans-β-nitrostyrene (11), 1, 4-benzoquinone (19), methyl 1, 4-naphtoquinone-5-carboxylate (21), 1, 4-naphthoquinone (24), juglone (26), 5-methoxy-1, 4-naphthoquinone (28), naphthazarin (31), and naphthazarin dimethyl ether (33). In addition, 5-(N, N-dimethylamino)-2, 4-pentadienenitrile (tert-aminodienylnitrile 37) was synthesized by condensation of crotononitrile (36) with 3. The reactivity of 37 was investigated with dimethyl 2-butynedionate (5), and 2-cyclohexenone (9).