The Guerbet reaction uses one of these reactions as the intermediated linking step, while one variation of this reaction uses an enamine catalyst and 
The Guerbet reaction uses one of these reactions as the intermediated linking step, while one variation of this reaction uses an enamine catalyst and is named for Hajos and Parrish. Crimmins' thiazolium is an update to one common auxillary catalyst used in this reaction known as the Evans oxazolidinone, while most variations of it have a stereoselectivity that can be explained by invoking a six-member chair configuration transition state in the Zimmerman-Traxler model. It begins with a deprotonation on the alpha carbon of a carbonyl compound, with the resulting enolate then attacking another carbonyl to create a namesake product. For 10 points, name this condensation reaction from organic chemistry that creates beta-hydroxycarbonyls.
The Guerbet reaction uses one of these reactions as the intermediated linking step, while one variation of this reaction uses an enamine catalyst and is named for Hajos and Parrish.
{Aldol} condensation