Each of 6A-azido-6A-deoxy-6X-O-(2-naphthalenesulfonyl)-~cycl~x~s (X=B-G) was prepared by the reaction of Bazido-6-deoxy-fi-cyclodextrin with 2-naphthalenesulfonyl chloride, isolated, and structurally determined. Construction of artificial enzymes (or receptors) by chemical modification of cyclodextrins has been extensively studied. While monosubstitution of primary hydroxyls of cyclodextrins allowed simple designing of enzymes (or receptors),2 Ttransannular disulfonylation (disulfonate capping) developed new aspect of synthesis of symmetrically bifunctionalized enzyme (or receptor) mimics. 2y3 We also developed convenient preparation and effective separation of 6A,6X-bis(O-arenesulfonyl)-cyclodextrins.4 However, more sophisticated artificial enzymes (or receptors) should possess two different functional groups at desirable positions.
Strategy of preparation of these artificial enzymes (or receptors) may be divided into three types as shown in Scheme 1, where X and Y are activated primary hydroxyls such as sulfonates and Z1 and Z2 are functional groups. Since the product composition of the type (1) reaction is statistical, particular association between Z1 and Z, (neither between Z1 and Z1 nor between Z2 and Z2) should be necessary for the formation of (Zl,Z2) in a composition more than 50% (statistical value). The type (2) reaction utilizing an unsymmetrically, transannularly disulfonylated cyclodextrin (X-Y) has been reported. This method permitted predominant production of (Zl&), although information was not given with respect to the relative positions of Z1 and Z2.5 Recently, we reported preparation and isolation of regiochemically pure (X,Y) where X has more reactive than Y.6
Six years ago, we reported the type (3) method, i.e., the 6-0-sulfonylation of f&azido+deoxy-P-cyclodextrin with mesitylenesulfonyl chloride in pyridine.7 Although this type method permitted isolation of (Zl,X) which was pure with respect to the ,q&& positions ( gAvgB-,6 ,6 A c-, or 6A,6D-positions) of the substituents, each isomer (for example, the 6A,6B-isomer) was most likely a mixture of two positional isomers (6A,6B-and 6A,6G-isomers) which were not separable. In this paper, we describe preparation of a complete set of