Regiospecific sulfonation of secondary hydroxyl groups of .alpha.-cyclodextrin. Its application to preparation of 2A2B, 2A2C-, and 2A2D-disulfonates

Abstract

Specific sulfonation on a secondary hydroxyl group (C-2-OH or C-3-OH) of -cyclodextrin was elucidated. A reaction of -cyclodextrin with m-nitrobenzenesulfonyl chloride exclusively gave the C-2-sulfonate, while /3-naphthalenesulfonyl chloride selectively afforded the C-3-sulfonate. The former reaction also gave selectively 2A2B-, 2A2C-, and 2A2D-disulfonates as the products of disulfonation. They were well separated by reversed-phase column chromatography, isolated, and converted to corresponding di-manno-epoxides. Structural determinations of the disulfonates and the diepoxides were made from their

Enhanced single-isomer separation and pseudoenantiomer resolution of new primary rim heterobifunctionalized α-cyclodextrin derivatives

“…In contrast, heterobifunctionalized CDs have been prepared via multistep synthesis (depending on the steric hindrance of the moiety on the CD scaffold and on the bulkiness of reagents [ 22 ]) or by modification of homobifunctionalized CDs [ 23 – 24 ]. These and previous studies [ 25 – 26 ] confirmed that CD derivatives with bulky substituents such as tosyl groups can be separated by reversed-phase column chromatography and HPLC separation methods can be easily scaled up to obtain grams of pure regioisomers. However, to the best of our knowledge, no such comparative regiochemical study of homobifunctionalized α-CDs prepared from the most commonly used CD intermediates has been conducted thus far although the regioisomer pattern of these intermediates is crucial for the investigation of new single isomer CDs with reproducible and definite structures.…”

“…The synthetic approach started with the preparation of 6 A ,6 X -capped α-CD derivatives. From special capping agents previously used on α-CD [ 17 – 18 26 ], we selected the most common, relatively inexpensive and commercially available m -benzenedisulfonyl chloride and biphenyl-4,4´-disulfonyl chloride. The prepared 6 A ,6 X -disulfonyl-capped CDs 2 and 3 were immediately converted to the more stable 6 A ,6 X -diazido-α-CDs 4 to prevent hydrolysis.…”

Cyclodextrin-based enzyme models. Part 1. Synthesis of a tosylate and an epoxide derived from heptakis(6-O-tert-butyldimethylsilyl)-β-cyclodextrin and their characterization using 2D NMR techniques. An improved route to cyclodextrins functionalized on the secondary face

“…However, in contrast to functionalization of the primary face of cyclodextrins, which has been extensively studied, the chemistry available for functionalization of the secondary face is less well developed. Preparative methods for secondaryfunctionalized cyclodextrins generally involve moderate yields and purification of synthetic intermediates by reverse-phase chromatography, which is scale-limited (5)(6)(7)(8).…”

Selective Recognition of Endocrine Disruptors by Fluorogenic γ-Cyclodextrin Having Pyrene-Tosyl Substituents on Hetero Rims

“…11,12 Although, sulfonation of the secondary hydroxyl groups of the CyDs as precursors of functional CyDs has been reported to be more difficult. [13][14][15][16][17][18][19] Teranishi was prepared various sulfonyl CyDs at the C-2 position from sulfonyl imidazole using molecular sieves (4A), in which these procedures are conveniently succeeding under mild condition. [20][21][22][23] Therefore, it would be interesting to design a molecular sensory system of a new fluorescent CyD labeled at both the upper and lower rims.…”