2-Ethylhex-2-enal

Ethylhexan-1 -ol is a useful building block for the pharmaceutical, food, cosmetic and chemical industries. The reduction of 2-ethylhex-2-enal to CS )-2-ethylhexan-l -ol by baker s... 

Aldehyde dimer may undergo dehydration to give an a, -unsaturated carbonyl. From butanal, the conjugated carbonyl is ethylpropylacrolein (Equation 2.10). The conjugated system of this material competes for coordination sites on the rhodium catalyst so that hydroformylation inhibition is observed.[8] The formation of 2-ethylhex-2-enal can be limited by minimizing the concentration of dimers. Dimers are removed along with the product in a liquid recycle separation system. 

Equation 2.10. Formation of 2-ethylhex-2-enal via aldol condensation of butanal... 

By far the most important compounds of this type are the a,/ -unsaturated aldehydes and ketones, of which the simplest general representation is (8) and (9) respectively. Branching may be present at either or both of the a- or p- positions as for example in 2-ethylhex-2-enal (10) and 4-methylpent-3-en-2-one (11). Compounds where the carbon-carbon double bond is terminal are acraldehyde [(8), R=H], and the alkyl (or aryl) vinyl ketones [(9), R = H, R = alkyl, aryl etc.]. 

All the steps of this reaction are reversible but the position of the equilibrium is significantly in favour of the aldol, which generally may be obtained when the reaction is carried out at room temperature or below, followed by extraction and careful distillation under reduced pressure. When the required product is the unsaturated aldehyde the reaction is carried out at a higher temperature, and dehydration of the aldol occurs readily (e.g. 2-ethylhex-2-enal, Expt 5.212). In the case of aldehydes with only one a-hydrogen atom, aldol formation occurs but the resulting / -hydroxyaldehyde cannot undergo the dehydration step. 

Aorolein, 2-ethyl-3-propyl- AI3-06105 CCRIS 4645 EINECS 211-448-3 2-Ethylhexenal 2-Ethyl-2-hexenal 2-Ethylhex-2-enal 2-Ethyl-2-hexen-1-al 2-Ethylhex-2-en-1-al a-Ethyl-p-propyiacrolein 2-Ethyl-3-propylacryl-aldehyde 2-Ethyl-3-propylacrolein 2-Hexenal, 2-ethyl- HSDB 1120 NSC 4787,... 

Synonyms 2-Ethylhex-2-enal 2-Ethyl-3-propylacrolein o-Ethyl-P-N-propylacrolein... 

Ethylhex-2-enal. See 2-Ethyl-2-hexenal, a-Ethylhexenal. See 2-Ethylhexenal Ethyl 3-hexenoate... 

Another reaction of interest, in which a bifunctional catalyst (HT plus an hydrogenation function) works well is the conversion of n-butyraldehyde into 2-ethylhex-enal. Aldol and related condensation reactions such as Knoevenagel and Clai-sen-Schmidt condensations are also widely used in fine chemicals and specialty chemicals, for example, flavors and fragrances, industries. 

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