Formation of and Z Enolates

Aldol Product Stereochemistry Depends on Enolate Stereochemistry FORMATION OF ( ) AND (Z) ENOLATES 

Introduction to Strategies for Organic Synthesis, First Edition. Laurie S. Starkey. 2012 John Wiley Sons, Inc. Published 2012 by John Wiley Sons, Inc. 

If a bulkier base is used, such as lithium tetramethyl piperidide (LTMP), or in the case of ester enolate formation in which the Ri group (actually OR ) is smaller, the ( )-enolate is major. The Ireland model uses the possible six-membered, chair-like, cyclic transition states to help rationalize the stereoselectivity of enolate formation. 

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