Reacción #6087

Ecuación de reacción

water

methoxymethyltriphenylphosphonium chloride

methyl 4-oxobutanoate

n-butyllithium

→

liquid

Methyl 5-methoxypent-4-enoate

Disolventes

tetrahydrofuran

hexane

tetrahydrofuran

Condiciones de reacción

Tratamiento posterior

1. 1
   Temperaturato warm to room temperature
2. 2
   TemperaturaAfter cooling to -78° C
3. 3
   Otroto reach room temperature
4. 4
   Extracciónextracted twice with ether
5. 5
   LavadoThe ether extracts were washed with saturated sodium chloride solution
6. 6
   Otrodried
7. 7
   Concentraciónconcentrated in vacuo
8. 8
   LavadoThis was eluted through 250 g silica gel with 1 l ether-hexane 1:1

Procedimiento

34.3 g (0.1 mole) methoxymethyltriphenylphosphonium chloride was suspended in 100 ml dry tetrahydrofuran and cooled to -78° C. under argon. 75 ml (0.1 mole) n-butyllithium solution in hexane was added and the solution allowed to warm to room temperature. After cooling to -78° C. 12.1 g (0.0105 moles) methyl 4-oxobutanoate was added in 50 ml tetrahydrofuran. The solution was allowed to reach room temperature then poured into water and extracted twice with ether. The ether extracts were washed with saturated sodium chloride solution dried and concentrated in vacuo. This was eluted through 250 g silica gel with 1 l ether-hexane 1:1 to give a faintly yellow liquid 9.2 g containing both (Z) and (E) enol ethers.

Fuente