Darstellung, Struktur und konformatives Verhalten gespannter Adamantanophane

Preparation, Structure, and Conformational Behaviour of Strained AdamantanophanesExchange of aromatic units (e.g. benzene) for aliphatic/alicyclic building blocks (e.g. adamantane) in cyclophanes leads to new molecules of the “araliphane” type. In the framework of this concept the araliphanes 3(a), 5–7a, 10(a), and 11 are synthesized. Their stereochemical behaviour differs significantly from that of their aromatic counterparts as shown by NMR studies and X‐ray crystallographic analyses. Extremely upfield‐shifted signals of the intraanular adamantane hydrogen atoms are found as well as a planar chiral adamantanophane. A Diels‐Alder addition of 8 to the benzene ring of 6 yields 9. Complete replacement of benzene units by adamantane leads to the fully aliphatic/alicyclic “aliphanes”. The crystal structure of 15 is described.