Enolates cyclic, 6-membered, axial attack

Alkylation of cyclic enolates is stereoselective, with reaction taking place on the less hindered face (four- or five-membered rings) or via axial attack (six-membered rings)... 

Lo be driven by Lhe need for Lhe transition state and product to have a chair rather than a boat conformation. This can override the preference for substituents to go into equatorial positions. The choice of axial attack controls the stereoselectivity of reactions of cyclohexenes (and, as you will see, their epoxides), six-membered cyclic enolates, and six-membered cyclic enones. 

---

See also in sourсe #XX -- [ ]

---