2-Undecanone → 7-Methylhexadecene-1-ol

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

Into a dried 5 L, 3 neck round bottom flask fitted with mechanical stirring, nitrogen inlet, dropping funnel, thermometer and nitrogen outlet is added 70.2 g of 60% sodium hydride (1.76 mol) in mineral oil. The mineral oil is removed by washing with hexanes. Anhydrous dimethyl sulfoxide (500 ml) is added to the flask and the mixture is heated to 70° C. until evolution of hydrogen stops. The reaction mixture is cooled to room temperature followed by addition of 1 L of anhydrous tetrahydrofuran. (6-hydroxyhexyl) triphenylphosphonium bromide (443.4 g, 1 mol) is slurried with warm anhydrous dimethyl sulfoxide (50° C., 500 ml) and slowly added to the reaction mixture through the dropping funnel while keeping it at 25-30° C. The mixture is stirred for 30 minutes at room temperature at which time 2-undecanone (187 g, 1.1 mol) is slowly added through a dropping funnel. Reaction is slightly exothermic and cooling is needed to maintain 25-30° C. The mixture is stirred for 18 hr. and then poured into a 5 L beaker containing 1 L purified water with stirring. The oil phase (top) is allowed to separate out in a separatory funnel and the water phase is removed. The water phase is washed with hexanes (500 ml) and the organic phase is separated and combined with the oil phase from the water wash. The organic mixture is then extracted with water 3 times (500 ml each) followed by vacuum distillation to collect the clear, oily product (132 g) at 140C and 1 mm Hg.

Herkunft & Nachweise