Propanal → 3,5,5-Trimethylhexanal

Participants

Reaction Steps

128 g (4 moles) of methanol and 2 g (0.05 mole) of NaOH were initially taken under nitrogen in a reaction flask and were refluxed. A mixture of 142 g (1 mole) of 3,5,5-trimethylhexanal and 116 g (2 moles) of propionaldehyde was added dropwise to this solution in the course of 10 minutes. The resulting reaction mixture was kept at the boil for 1 hour (h) and then brought to pH 4-5 with an 80% strength aqueous acetic acid solution. After washing twice with water, the organic phase was separated off and worked up by fractional distillation. 32 g of unconverted 3,5,5-trimethylhexanal, as light ends, and 113 g of 2,5,7,7-tetramethyl-2-octenal (bp.=108°-111° C./14 mbar) were obtained, corresponding to a selectivity of 81%, based on trimethylhexanal; nD25 =1.4580.

Provenance & Evidence