Reacción #525110

Ecuación de reacción

ethylene dibromide

2-bromopropene

4-hexynal

( c )

4-Hexynal

ammonium chloride

→

2-methyloct-1-en-6-yn-3-ol

Rendimiento 85.0%

Disolventes

tetrahydrofuran

—

ice-salt

Condiciones de reacción

Tratamiento posterior

1. 1
   SecadoMagnesium (14.4 g, 0.6 g atom) was dried in a 250 ml flask
2. 2
   Otrofitted
3. 3
   Temperaturawith reflux
4. 4
   workup.ADDITIONcondenser, mechanical stirrer and addition funnel
5. 5
   workup.ADDITIONwas added dropwise at such a rate as
6. 6
   Temperaturato maintain
7. 7
   Temperaturareflux without external heating
8. 8
   workup.STIRRINGThe reaction mixture was stirred for 2 hours at room temperature
9. 9
   Extracciónthe product was extracted with ether

Procedimiento

Magnesium (14.4 g, 0.6 g atom) was dried in a 250 ml flask fitted with reflux condenser, mechanical stirrer and addition funnel. After initiation of reaction under dry N2 with about one ml ethylene dibromide in 70 ml tetrahydrofuran, 36.0 g (0.30 mole) 2-bromopropene was added dropwise at such a rate as to maintain reflux without external heating. The Grignard solution was then stirred until it cooled to room temperature (30 minutes-1hour). It was then cooled further to -15° in ice-salt, and the total crude 4-hexynal from part (c) above was added dropwise over 15 minutes. The reaction mixture was stirred for 2 hours at room temperature, saturated ammonium chloride solution was added and the product was extracted with ether. There was obtained 23.50 g of 2-methyloct-1-en-6-yn-3-ol (85%, based on 4-methyl hexynoate) as a pale yellow oil.

Fuente