3. The progress of the reaction can be monitored by TLC by working up a sample of the reaction mixture: filter through Celite, cool to 0°C, and acidify to pH 1 with
10% aqueous HCl. The solid that precipitates is isolated by filtration and dissolved in
dimethylformamide (DMF) for TLC analysis on
Merck precoated-silica gel 60 plates with
methyl ethyl ketone-
methanol-water (4:1:1) as eluent, developed by dipping in
5% sulfuric acid-ethanol and heated to 450°C (e.g., with a
Bunsen burner). R
F values are 0.25 for
β-cyclodextrin, 0.5 for monotosylate and 0.65 for a second product, probably ditosylate.
7. Lit.
2 mp
160-162° (dec.). TLC shows a weak spot for ditosylate, and
1H NMR integration (aromatic region) shows this impurity to be 8-9%. The physical properties are as follows:
1H NMR (500 MHz, DMSO-d
6) δ: 2.42 (s, 3 H), 3.20-3.67 (m, 40 H), 4.16-4.20 (m, 1 H), 4.32 (d, 1 H, J = 9), 4.37-4.39 (m, 1 H), 4.45-4.48 (m, 2 H), 4.52-4.53 (m, 3 H), 4.77 (d, 2 H, J = 3.4), 4.83-4.84 (m, 5 H), 5.64-5.85 (m, 14 H), 7.42 (d, 2 H, J = 8.2), and 7.75 (d, 2 H, J = 8.2);
13C NMR (125 MHz, DMSO-d
6) δ: 21.3, 59.3, 59.6, 60.0, 69.0, 69.8, 71.9, 72.1, 72.2, 72.4, 72.5, 72.8, 73.0, 73.1, 80.8, 81.2, 81.4, 81.5, 81.7, 101.3, 101.9, 102.0, 102.3, 127.6, 129.9, 132.7, 144.9;
[α]D20 +131° (
dimethyl sulfoxide,
c 4).