SELF-INCLUSION COMPLEXES DERIVED FROM CYCLODEXTRINS - SYNTHESIS AND CHARACTERIZATION OF 6(A),6(B)-BIS-O-[P-(ALLYLOXY)PHENYL]-SUBSTITUTED BETA-CYCLODEXTRINS

The syntheses, structures, and spectroscopic properties of 6(A),6(B)-b is-O-[p-(allyloxy)phenyl]-substituted beta-cyclodextrins have been inv estigated. Selective activation of the 6(A),6(B)-hydroxy groups was ca rried out by treating heptakis(2,3-di-O-methyl)-beta-cyclodextrin (1) with 2,4-dimethoxybenzene-1,5-disulfonyl chloride to give 6(A),6(B)-bi ssulfonate ester 2 in a yield of only 3%. This material was treated wi th sodium p-(allyloxy)phenoxide in DMF to form 6(A),6(B)-bis-O-[p-(all yloxy)phenyl]-heptakis(2, 3-di-O-methyl)-beta-cyclodextrin (3), which had two isomers. One (3A) has the two p-(allyloxy)phenyl arms directed away from the cyclodextrin cavity, and the other (3B) has one of the p-(allyloxy)phenyl groups through the cavity to form a self-inclusion complex. When either 3A or 3B was treated with methyl iodide and sodiu m hydride, the resulting permethylated 6(A),6(B)-bis-O-[p-(allyloxy)ph enyl]heptakis(2, D),6(E),6(F),6(G)-penta-O-methyl-beta-cyclodextrin (4 ) was compo sed of two isomers, in which 4B is a self-inclusion comple x. 3A and 3B also can be converted into a mixture of 3A and 3B in stro ng base but not when melted in the absence of base. 4A and 4B do not i somerize. Detailed 1D and 2D NMR spectroscopic studies were carried ou t to characterize the structures of these new compounds, and molecular mechanics techniques were used to explain the experimental facts.