Reaktion #55926

Reaktionsgleichung

potassium phosphate monobasic sodium hydroxide

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

sodium methoxide

ether

→

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

Ausbeute 35.0%

Lösungsmittel

methanol

methanol

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.STIRRINGThe resulting mixture is stirred for 30 minutes after which it
2. 2
   SonstigeThe organic phase is separated
3. 3
   Trocknendried (Na2SO4)
4. 4
   Sonstigeevaporated in vacuo
5. 5
   Sonstigeto give the crude product (15.4 g)
6. 6
   SonstigeThis material is purified by column chromatography on silica gel (300 g, 2% ethyl acetate in hexane)

Vorschrift

A solution of methyl 3,7-dimethyl-4-nitro-6-octenoate (24.55 g, 0.107 m) in methanol (10 ml) is added dropwise to a solution of sodium methoxide (6.37 g, 0.118 m) in methanol (250 ml) at room temperature under nitrogen. The mixture is stirred for 1 hour, added to a mixture of 20% titanous chloride (170 ml, 0.267 m) and pH 7 buffer (potassium phosphate monobasic-sodium hydroxide buffer) solution (340 ml). The resulting mixture is stirred for 30 minutes after which it is treated with ether (1 l). The organic phase is separated, dried (Na2SO4) and evaporated in vacuo to give the crude product (15.4 g). This material is purified by column chromatography on silica gel (300 g, 2% ethyl acetate in hexane) to give methyl 3,7-dimethyl-4-oxo-6-octenoate as a colorless liquid (6.8 g, 35%).

Quelle