反応 #3099

反応方程式

methyl 3-oxo-6-octenoate

5-(2-nitrovinyl)-1,3-benzodioxole

ethyl acetate hexane

→

title compound

収率 82.0%

Methyl 2-(4-hexenoyl)-4-nitro-3-(1,3-benzodioxole-5-yl)butyrate

収率 82.0%

溶媒

isopropanol

THF

反応条件

後処理

1. 1
   その他consumption of ketoester
2. 2
   濃縮The solution was concentrated in vacuo and flash
3. 3
   その他chromatographed on silica gel eluting with 18% ethyl acetate in hexane

実験手順

A solution of methyl 3-oxo-6-octenoate (502 mg, 2.95 mmol) in 10 mL of isopropanol was added to a solution of 5-(2-nitrovinyl)-1,3-benzodioxole (712 mg, 3.69 mmol) in 10 mL THF, then DBU (22 μL, 0.15 mmol) was added. The resulting reddish solution was stirred at room temperature for 20 minutes. TLC (ethyl acetate-hexane, 1:3) indicated complete consumption of ketoester. The solution was concentrated in vacuo and flash chromatographed on silica gel eluting with 18% ethyl acetate in hexane to produce 879 mg (2.42 mmol, 82%) of the title compound as a mixture of diastereomers in a 1:1 ratio. 1H NMR (CDCl3, 300 MHz) δ 1.55-1.66 (m, 3H), 2.02-2.17 (br m, 1H), 2.20-2.37 (m, 1.5H), 2.49-2.76 (m, 1.5H), 3.57 (s, 1.5H), 3.74 (s, 1.5H), 3.97 (d, J=7.5H, 0.5H), and 4.05 (d, J=8 Hz, 0.5H), 4.10-4.20 (m, 1H), 4.68-4.82 (m, 2H), 5.06-5.52 (m, 2H), 5.95 (2s, 2H), 6.65 (m, 1H), 6.68 (br s, 1H), 6.75 (d, 7.5 Hz, 1H). MS (DCl/NH3) m/e 381 (M+NH4)+. Anal calcd for C18H21NO7 : C, 59.50; H, 5.82; N, 3.85. Found: C, 59.32; H, 5.71; N, 3.72.

出典