2A,2B-, 2A,2C-, and 2A,2D-Bis-O-(p-tolylsulfonyl)-β-cyclodextrins

Abstract

A mixture of the title ditosylates was prepared by the reaction of β-cyclodextrin with dibutyltin oxide and tosyl chloride. Each ditosylate was isolated by reversed-phase column chromatography and the structure was assigned on the basis of conversion into a known compound or hydrolysis with Taka amylase A.

Methods for Selective Modifications of Cyclodextrins

“…In this strategy, each reaction is carefully chosen to give a high yield and the product should be easily separable and purifiable; however, the overall yield of the final product is often very small. An example of the third category is ditosylation of the secondary side of cyclodextrin …”

Construction of a Fused Polycyclic Wall within the Cyclodextrin Belt To Ensure a Distorted Cavity: An Unusual trans‐Diequatorial Ring‐Opening Reaction of Cyclodextrin Epoxide Rings

“…2 I ,3 I ‐ manno ‐Epoxy‐β‐CD 1b 18,19,29 and 2 I ,3 I :2 M ,3 M ‐di‐ manno ‐epoxy‐β‐CDs19,29 3a − 3c were treated with aqueous alkali to give 2b (63%), 4a (50%), 4b (50%), and 4c (63%), respectively.…”

“…The filtrate was subjected to column chromatography on a Merck Lobar Rp 18 C‐type column with a gradient elution from 20% (500 mL) to 50% aqueous MeOH (500 mL) to give 4a (189 mg, 50%). Similarly, 2 I ,3 I :2 III ,3 III ‐ or 2 I ,3 I :2 II ,3 II ‐di‐ manno ‐epoxy‐β‐CD19,29 ( 3b , 118 mg, 0.11 mmol or 3c , 377 mg, 0.34 mmol, respectively) afforded 4b (59 mg, 50%) or 4c (235 mg, 63%).…”

“…3 I ,2 II :3 M ,2 N ‐Dianhydro‐β‐CDs (4a−c) ([M,N]: [IV,V], [III,IV], and [II,III]): A solution of 2 I ,3 I :2 IV ,3 IV ‐di‐ manno ‐epoxy‐β‐CD 3a 19,29 (380 mg, 0.35 mmol) in 0.25 M NaOH (40 mL) was stirred for 3 d at 80 °C, neutralized with 1 M HCl, and filtered. The filtrate was subjected to column chromatography on a Merck Lobar Rp 18 C‐type column with a gradient elution from 20% (500 mL) to 50% aqueous MeOH (500 mL) to give 4a (189 mg, 50%).…”

The first hetero-bifunctionalization of the secondary face of β-cyclodextrin: selective and efficient conversion of the A-ring of a 2A,2B-disulfonate to 2A,3A-epoxymannoside

“…The positional alternative 2b was structurally determined by transformation to diepoxide 5, which gave the same spectral data as the authentic compound. 7 A kinetics study indicated that, in comparison with 2-O-mesitylenesulfonyl-b-CD, the A-ring of 1 reacted 2.7 times faster while the B-ring reacted 5.0 times slower in a phosphate buffer solution (pH 12.0, 0.1 M) at 15 uC. The A,C-and A,Dregioisomers of 1 did not display meaningful ring-preference, and the corresponding intermediate epoxy-sulfonates did not accumulate as the major products.…”