Diisopropylamine → Cyclododeca-4,8-diene-1-carbaldehyde

Participants

Reaction Conditions

Reaction Steps

i-Pr2NH [80 g; 0.79 mol] was added to tetrahydrofuran (THF) (100 ml), cooled to −30° C., and n-BuLi [40 ml of 2.5 M, 0.1 mol] added dropwise by syringe, under N2. (Trimethylsilyl)diazomethane (TMSCHN2) [50 ml; 1.9 M in hexane; 0.095 mol] was added dropwise to this lithium diisopropylamide (LDA) solution at −70° C. After complete addition, a solution of 4,8-cyclododecadien-1-one [14.2 g; 0.08 mol] in anhydrous THF (50 ml) was added, and the reaction mixture allowed to stir for 1 hour at −70° C., then allowed to reach ambient temperature. It was, subsequently, refluxed for 3 hours. Most of the THF was removed in vacuo, Et2O (300 ml) was added, and the reaction mixture poured into ice-water. After extraction into Et2O, the solvent was removed, the residue redissolved in ethyl acetate (300 ml), and silica gel (100 g) added, together with H2O (1 ml). The mixture was stirred overnight under N2, the mixture concentrated in vacuo, then loaded onto a short silica column. Flash chromatography using a mixture of hexane (90%) and Et2O (10%) as eluent, gave 4,8-cyclododecadiene carboxaldehyde (QRM 2815) as a colourless oil (14.0 g).

Provenance & Evidence