(E)-1-Dimethylamino-4,4-dimethoxy-pent-1-en-3-one synthesis

Yield:106157-94-2 87%

Reaction Conditions:

with boron trifluoride diethyl etherate for 48 h;Reflux;

Steps:

1-(N,N-Dimethylamino)-4,4-dimethoxypent-1-en-3-one (7)

Compound 6 (1.0 mL, 7.47 mmol), N,N-dimethyl formamide dimethylacetal (1.98 mL, 13.5 mmol), and boron trifluoride etherate (40 LL, 0.32 mmol) were refluxed for 2 days. Then, the solution was concentrated under reduced pressure. The residue was purified by column chromatography (CH2Cl2:MeOH=20:1) to give compound 7 (1.22 g, 87%) as a yellow liquid. 1H NMR (300MHz, CDCl3) δ 1.42 (s, 3H), 2.89 (s, 3H), 3.12 (s, 3H), 3.26 (s, 6H), 5.51 (d, 1H, J = 12.5Hz), 7.73 (d, 1H, J = 12.5Hz). 13C NMR (75MHz, CDCl3) δ 21.1, 37.1, 44.8, 49.5, 90.8, 102.3, 154.4, 194.2. FAB-MS (m/z) 188 [M+H]+.TLC: Rf 0.20 (CH2Cl2:MeOH=40:1).

References:

Kamo, Masahiro;Ito, Miu;Toma, Tsugumasa;Gotoh, Haruna;Shimozono, Rie;Nakagawa, Riko;Koga, Ryoko;Monde, Kazuaki;Tateishi, Hiroshi;Misumi, Shogo;Otsuka, Masami;Fujita, Mikako [Bioorganic Chemistry,2021,vol. 107,art. no. 104627] Location in patent:supporting information