SYNTHESIS AND CONFORMATIONAL STUDIES OF NOVEL CALIXARENE-ANALOGOUS MACROCYCLIC [3.1.1]METACYCLOPHANES

Hydroxy[3.1.1]metacyclophane 4c, which is regarded as an unsymmetric o r uncomplete ''homocalixarene'' bearing a propane bridge, has been syn thesized using Nafion-H catalyzed cyclobenzylation. A novel ''pendulum '' type motion steered by intramolecular hydrogen bonding has been obs erved. Demethylation of compound 4c with BBr3 in methylene dichloride was carried out at room temperature for 3 h to afford the dihydroxy[3. 1.1]metacyclophane 4b in 74% yield along with the triol 4a in 25% yiel d. Triol 4a was tri-O-alkylated xith methyl iodide in the presence of NaH to yield partial-cone conformer 4d in quantitative yield. Similarl y, a significant amount of partial-cone conformer 5 results in the cas e of O-alkylation of 4a with N,N-diethylchloroacetamide. H-1-NMR titra tion of partial-cone amide 5 with NaSCN clearly demonstrates that a 1: 1 complex is formed which is stable on the NMR time scale.