The order of activity at 150 °C and 1 a The order of activity at 150 °C and 1 a Selectivity to 2-ethyl-2-hexenal was 100% for both pure and mixed isomer feed.

RCH 2 CH O + •• OH •• • • – RCHCH O + •• HOH –•••• •• pK a = 16-20 pK a = 16 Some thoughts... •• RCHCH O •• • • – RCH 2 The Aldol Condensation. What about nucleophilic addition of enolate to aldehyde? The nucleophile is generally an enolate of an aldehyde or ketone attacking another aldehyde or ketone molecule. If you follow the mechanism closely, you’ll see that a carbanion is formed at the alpha carbon of the carbonyl carbon (which is stabilized by the carbonyl group). Aldol condensation is a nucleophile attack on a carbonyl to make a ketone or aldehyde of β-hydroxy.

Vapor-phase self-aldol condensation of butanal was performed over various solid catalysts. Enolate ions are nucleophiles. Among the tested catalysts, SiO 2-Al 2 O 3, Nb 2 O 5 and TiO 2 showed relatively high catalytic activity for the formation of aldol condensation product, 2-ethyl-2-hexenal, whereas all the catalysts deactivated rapidly.

Alkali metal zeolites and metal oxides were used for the aldol condensation of n-butanal to 2-ethyl-2-hexenal. Vapor-phase aldol condensation of butanal to form 2-ethyl-2-hexenal was carried out over several oxide catalysts such as SiO 2-Al 2 O 3, Al 2 O 3, ZrO 2, and SiO 2. An acidic or basic solution can catalyze the condensation of aldol. The enolate of the aldehyde attacks a molecule of un-enolised aldehyde. Aldol condensations are important in organic synthesis, because they provide a good way to form carbon–carbon bonds.

Aldehydes undergo nucleophilic addition. Give the curly arrows a try and post what you end up with :) $\endgroup$ – NotEvans.

A basic solution contains comparable amounts of the aldehyde and its enolate.

Catalysts with moderate and strong acid sites such as Al 2 O 3 and SiO 2-Al 2 O 3 were active for the reaction in the initial period, whereas they deactivated rapidly. For example, the Robinson annulation reaction sequence features an aldol condensation; the Wieland–Miescher ketone product is an important starting material for many organic syntheses. The resulting intermediate eventually loses water to give your product, as drawn. $\begingroup$ The reaction is a self aldol condensation. The condensation of ethanol to butanol was investigated over a commercial hydroxyapatite catalyst in the 350–410 °C temperature range.