反应详情

Dry, freshly crystallised p-toluenesulphonyl chloride (1.86 g, 9.8 mmol) and 4-dimethylaminopyridine (10 mg, 0.082 mmol) were added to a solution of alcohol 5 (2.00 g, 8.15 mmol) and triethylamine (2.6 ml, 18.75 mmol) in dichloromethane (20 ml) at 5° C. with stirring. The resulting solution was protected from moisture and kept at 5° C. until all the starting material 5 had reacted (33 h, TLC). A colourless solid, presumably triethylamine hydrochloride, crystallised out of the reaction, and was filtered away. The filtrate was diluted with dichloromethane to a volume of 90 ml, and washed with water (2×20 ml), brine (20 ml), dried over Na2SO4, and concentrated to give the crude tosylate 7 as white solid. This material was purified by dissolving in ether (ca. 330 ml), filtering through celite 545 on a wad of cotton wool to give 2.95 g (90%) of 7. 1H NMR (200 MHz, CDCl3) 7.78 (m, 2H), 7.35 (d, 2H), 4.09 (m, 2H), 4.09 (m, 2H), 3.90 (m, 2H), 3.73 (m, 1H), 2.95 (m, 2H), 1.51 (s, 6H), 1.44 (s, 9H).

1. customDry
2. customkept at 5° C. until all
3. customhad reacted (33 h, TLC)
4. customA colourless solid, presumably triethylamine hydrochloride, crystallised out of the reaction
5. filtrationwas filtered away
6. additionThe filtrate was diluted with dichloromethane to a volume of 90 ml
7. washwashed with water (2×20 ml), brine (20 ml)
8. dry with materialdried over Na2SO4
9. concentrationconcentrated
10. customto give the crude tosylate 7 as white solid
11. customThis material was purified
12. dissolutionby dissolving in ether (ca. 330 ml)
13. filtrationfiltering through celite 545 on a wad of cotton wool