Commercial Syntheses via the Aldol Condensation

Aldols are useful in synthesis. For example, acetaldehyde is converted commercially to crotonaldehyde, 1-butanol, and butanal using the aldol condensation. 

The particular product obtained in the hydrogenation step depends on the catalyst 

Butanal is the starting material for the synthesis of the mosquito repellent 6-12 (2-ethylhexane-l,3-diol). The first step is an aldol condensation, and the second step is reduction of the aldehyde group to a primary alcohol. 

The aldol condensation is also used in nature to build up (and, in the case of reverse aldol condensations, to break down) carbon chains. 

PROBLEM 9.29 2-Ethylhexanol, used commercially in the manufacture of plasticizers and synthetic lubricants, is synthesized from butanal via its aldol product. Devise a route to it. 

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