Novel Method to Prepare Dihydroxy Permethylated beta-Cyclodextrin Isomeric Intermediates for Bifunctional Enzyme Mimics.
Natural beta-cyclodextrin was treated with 3.5 equiv of tert-butyldimethylsilyl chloride and then with NaH and MeI in the same reaction vessel to give a mixture of oligosilyl-substituted permethylated beta-cyclodextrins. The mixture was treated with NH(4)F and the resulting 6(A),6(D)-(1), 6(A),6(C)-(2), and 6(A),6(B)-(3) dihydroxy permethylated beta-cyclodextrins were isolated in 7.6-8.9% yields by two silica gel chromatographic separations. The structures of 1-3 were verified by comparison of spectral properties with a known diol (2) or preparing known derivatives (1 and 3). This is a superior way to prepare and isolate dihydroxy permethylated beta-cyclodextrin intermediates for bifunctional enzyme mimics.
Chen
Zhen
Z
Department of Chemistry & Biochemistry, Brigham Young University, Provo, Utah 84602.
Bradshaw
Jerald S.
JS
Shen
Yu-Feng
YF
Habata
Yoichi
Y
Lee
Milton L.
ML