Magnesium enolates Reformatsky reaction

Several workers have observed aldol reactions with enolates prepared by reductive removal of an o-heteroatom from a carbonyl compound. The classic example is the Reformatsky reaction, which is reviewed in Volume 2, Chapter 1.8. Dubois and coworkers have employed this method for the preparation of magnesium enolates. An important example from this study, which stimulated much of the subsequent work on aldol stereoselectivity, is shown in equation (21). 

There are several condensation reactions that use zinc enolates rather than sodium, magnesium, or lithium enolates. These are usually categorized as a classical Reformatsky reaction or as a modified Blaise reaction. 

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