Synthesis and Conformational Properties of the Sterically Crowded D3d -Symmetric all-trans Hexa(spirotetrahydrofuranyl)cyclohexane System.

An unprecedented high barrier to ring inversion [Eq. (1)] prevents 1 from engaging in bifacial complexation with lithium ions. The X-ray crystal structure analysis of this hexaspiro compound corroborates the adoption of a cyclohexane chair with all six C-O bonds projected equatorially (1-eq).