novel method to prepare dihydroxy permethylated β-cyclodextrin isomeric intermediates for bifunctional enzyme minics

摘要

natural β-cyclodextrin was treated with 3.5equiv of tert-butydimethylsilyl chloride and then with NaH and MeI in the same reaction vessel to give a mixture of oligosilyl-substitutd permethylated β-cyclodextrins. The mixture was treated with NH_4F and the resulting 6~A,6~D-(2), and 6~A,6~B-(3) dihydroxy permethylated β-cyclodextrins were isolated in 7.6-8.9/100 yields by two silica gel chromatographic separations. The structures of 1-3 were verified by comparisom of spectral properties with a known diol (2) or preparing known derivations 91 and 3).