3,7-Dimethylocta-2,6-Dienal → 6,10-Dimethyl-4-hydroxy-2,5,9-undecatriene

Participants

Reaction Steps

12 g. of magnesium turnings were suspended under nitrogen in 250 ml. of dry tetrahydrofuran. Between 60° and 65°, 60 g. of 1-bromopropene dissolved in 50 ml. of tetrahydrofuran were added dropwise. During the addition, to prevent escaping of 1-bromopropene, the reflux condenser fitted on the reaction flask was cooled to -40°/-50°. When all Mg had reacted, the mixture was cooled to 20° and 76 g. of citral was added dropwise with cooling. After standing overnight, the mixture was poured into 1.5 liter of concentrated aqueous NH4Cl at 0°. The mixture was extracted 3 times with ether and the combined ether extracts treated as usual. After distillation, 6,10-dimethyl-4-hydroxy-2,5,9-undecatriene, b.p. 70°/0.1 Torr was obtained as a liquid with following constants : nD20 =1.4950; d420 =0.9145.

Provenance & Evidence