Dimethylformamide → HCID 86736281, compound

Participants

Reaction Steps

23.5 ml of n-butyllithium (about 2-M in n-hexane) are added dropwise under argon to a suspension of 20.4 g of 3-methylbutyl-trimethylphosphonium bromide in 80 ml of dry ether, a reaction temperature of about 20° being adhered to by slight cooling. Thereafter, the mixture is stirred at room temperature for a further 2 hours. The mixture is cooled to -10° and a solution of 5.4 g of (S)-4-chloro-2-methylbutyraldehyde in 5 ml of dry ether is added thereto. The separated precipitate is stirred for one hour without cooling bath, whereupon 100 ml of dimethylformamide are added dropwise at room temperature. The mixture is stirred at room temperature for 16 hours, hydrolysed on ice and extracted with ether. The ether phase is washed with water, dried and concentrated under reduced pressure. The residue is purified by adsorption on silicagel as well as on neutral aluminium oxide of the activities III and II (elution agent: n-hexane). After distillation under reduced pressure (13 mm Torr/90°), there are obtained 4.13 g (53%) of (S)-cis-1-chloro-3,7--dimethyl-4-octene. [α]D20 =+32.6° (2.15% in chloroform).

Provenance & Evidence