1,2-Dibromoethane → 2-Methyloct-1-en-6-yn-3-ol

Beteiligte Stoffe

Reaktionsschritte

Magnesium (14.4g, 0.6g atom) was dried in a 250ml flask fitted with reflux condenser, mechanical stirrer and addition funnel. After initiation of reaction under dry N2 with about one ml ethylene dibromide in 70ml tetrahydrofuran, 36.0g (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-1 hour). 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 23.50g of 2-methyloct-1-en-6-yn-3-ol (85%, based on 4-methyl hexynoate) as a pale yellow oil.

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