Reaktion #55925

Reaktionsgleichung

1,5-Diazabicyclo[5,4,0]undec-5-ene

2-methyl-5-nitro-2-pentene

methyl crotonate

→

methyl 3,7-dimethyl-4-nitro-6-octenoate

Ausbeute 42.0%

Lösungsmittel

methanol

methanol

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturThe resulting mixture is heated to 60°
2. 2
   Sonstigeis removed in vacuo
3. 3
   workup.ADDITIONThe residue is treated with ether (500 ml)
4. 4
   Waschenwashed with 2 N HCl (250 ml) and water (250 ml)
5. 5
   TrocknenThe organic layer is dried (Na2SO4)
6. 6
   Sonstigeevaporated in vacuo
7. 7
   Sonstigeto give 42.5 g of crude product
8. 8
   SonstigeThe crude product is purified by column chromatography on silica gel (500 g, ethyl acetate/hexane 2:98)

Vorschrift

1,5-Diazabicyclo[5,4,0]undec-5-ene (4 ml) is added to a solution of 2-methyl-5-nitro-2-pentene (25.0 g, 0.193 m) in methanol (200 ml). The resulting mixture is heated to 60° and methyl crotonate (30.85 g, 0.308 m) is added under nitrogen. The mixture is then stirred for 6 days at 60° after which it is cooled to room temperature and most of the methanol is removed in vacuo. The residue is treated with ether (500 ml) and washed with 2 N HCl (250 ml) and water (250 ml). The organic layer is dried (Na2SO4) and evaporated in vacuo to give 42.5 g of crude product. The crude product is purified by column chromatography on silica gel (500 g, ethyl acetate/hexane 2:98) to give methyl 3,7-dimethyl-4-nitro-6-octenoate (8.65 g, 42%).

Quelle