LDA-Controlled Crossed Aldol Product Formation

LDA-controlled crossed aldol product formation uses a strong base to guide a reaction between two different carbonyl compounds that both have alpha hydrogens. In a directed aldol reaction, this setup helps form one main crossed aldol product instead of a mixture.

A simple aldehyde and ketone reac...

The crossed aldol reaction between an aldehyde and a ketone – both containing an alpha-hydrogen, in aqueous sodium hydroxide forms a mixture of products.

Alternatively, a strong base like lithium diisopropylamide, abbreviated as LDA, minimizes the number of products.

The slow, dropwise addition of a ketone to the LDA solution irrev...